Transcript from an interview with Johann Deisenhofer, 1988 Nobel Laureate in Chemistry, 25 April 2007. Interviewer is Adam Smith, Editor-in-Chief of Nobelprize.org.
Hans Deisenhofer, welcome to this archival interview for Nobelprize.org. You're the co-recipient together with your mentor Robert Huber and your colleague Hartmut Michel, of the 1988 Nobel Prize in Chemistry which you received for the determination of the three-dimensional structure of a photosynthetic reaction centre. And the key point there is that it was the first high resolution image of a membrane bound protein which of course are very hard to crystallise. I wanted to start by exploring a little bit your scientific beginnings. You began as a physicist at the Technical University of Munich and then gradually migrated across to the field of biochemistry and I wonder what precipitated that gradual move.
Johann Deisenhofer: It happened during my masters thesis, which was in a topic on solid state physics, actually at liquid helium temperature. My mentor at that time, a professor at the TU Munich named Klaus Dransfeld, had begun to study biophysics so maybe the reason was he was appointed to give a course in biophysics by his faculty colleagues and he acquired a huge number of text books and his interest became more and more intense, and after a while it was no longer possible to talk to him about anything but biophysics.
So that transmitted itself to his students and he also started some projects in biophysics - I remember a Raman scattering experiment on, I've forgotten what protein. Biophysics was always present in the year or so I spent in his group and when it came to picking a mentor for my PhD I heard through the student pipeline that there was a new group being opened, being founded at the Max Planck Institute in Munich and I went for an interview. The group leader, or the Director, was Robert Huber and he accepted me as a student so that's how I came.
Along the path from physics to at least biophysics and biochemistry had you also had brushes with other branches of science? Had chemistry figured for instance at that stage?
Johann Deisenhofer: Not very much. I knew very, very little about chemistry and that was in part because among physicists at that time chemistry was considered a sort of a second-class science. You could hear people say Well, I mean, quantum mechanics describes everything and chemistry is the detail.
Where does that leave biology?
Johann Deisenhofer: Pretty stupid point of view, but they were present, and so in the curriculum for budding physicists chemistry played sort of a very minor role so we had to take one course, I think, in the first two semesters and a practical course, that was it. Compared to let's say, the math that we had to take at the same time, chemistry was indeed, or at that level was quite easy.
Do you think things are still the same when you study physics? Is chemistry still seen as a second-class subject?
Johann Deisenhofer: I don't know. I hope not because it is not justified as I learned the hard way later.
And you found yourself very much at home with Robert Huber, what was it about his style of leadership that particularly appealed to you?
Johann Deisenhofer: He was pretty young, only a few years older than I was, I think six years older and was very liberal, modern thinking. He had many ideas to do things differently than his mentor as always and he, for example, introduced the custom to address him as Robert and not as Professor Huber.
Which I imagine for Germany at that time was quite ...
Johann Deisenhofer: For Germany, it was unheard of. So it was great fun to be in this group and I liked it quite a lot.
And the resources were tremendous, I imagine, at the Max Planck?
Johann Deisenhofer: Yes. I mean I didn't pay attention to what things cost at that time. They had the modern machinery, the x-ray generators, even a computer controlled data collection, machines and so on and there was the Max Planck Institute for Plasma Physics in another part of Munich which had I think one of the fastest computers in Germany at that time an IBM 370 something or 360 91 ... I've forgotten the details but this was for anybody who had the calculations it was almost ideal conditions.
So I became a computer freak for a while at least and indeed at that time computing was one of the limiting resources in crystallography especially protein crystallography. If you look at the pictures of the beginning days of that field Max Perutz and his students. When they were collecting paper tapes ... I mean this was really pioneering work with a very, very limited availability of computing resources. And luckily this is all changed now, our laptops can do a lot more than the IBM machine at that time could do.
But things were changing fast when you got into the area? When you entered the fields things were beginning to change?
Johann Deisenhofer: Yes.
Compared to the norm now your development in science was perhaps somewhat slower than your first published paper which was with Klaus Dransfield when you were 28 I think and then you got your PhD and 31?
Johann Deisenhofer: Yes.
Was that the norm for the environment you were growing up in?
Johann Deisenhofer: No not really. It had to do with my personal history. I was not meant to become a scientist. I was meant to become a farmer and when it became clear that I would never be a good farmer I had lost one or two, three years at school and I had to catch up and for some reason the German army desperately wanted me so I had to lose another two years in the Army or one and a half years but in practice this amounted to two years and so that explains why I was relatively old when I got my PhD.
Do you think there were some advantages in being older at that point?
Johann Deisenhofer: I don't think so, no. It would have been better to get through the education much faster.
Johann Deisenhofer: And later I learnt to know some people who came from England or Australia and they were several years younger than me already had their PhD and I didn't see any negative in that.
Just referring to your childhood and the expectation that you would become a farmer. Are there, despite the fact that you didn't follow the family path, are there the nevertheless familiarly aspects to the way you work? Were there things that you brought particularly from your childhood?
Johann Deisenhofer: I enjoyed being on my own, being by myself. I certainly played with other kids and interacted but I had no problems with being on my own and that is still so. I think I enjoyed the occasions most when I had a well-defined project and I could solve the problems by myself.
It's a great thing to like one's own company, yes.
Johann Deisenhofer: Yes.
Having got your PhD and then embarked on post doctoral projects looking at the structures of a number of different proteins, you then had a momentous meeting with Hartmut Michel in 1982 when he revealed that he had crystallised a membrane bound protein. Did lights flash in your head at that moment and you thought this is the project for me?
Johann Deisenhofer: It took me a while because it was, at that time the larger protein the structure of each would be solved and it was not clear at all, there was no precedent whether the standard methods of structure determination would work and so I think everybody hesitated for a while but not very long. I like Hartmut because I knew him, I knew that he tried to crystallise membrane protein in a different group at the Max Planck led by Dieter Oesterhelt so we occasionally talked and then at some point it was clear that we would collaborate.
So how did that collaboration come about because having got to the point of having the crystals, I imagine there would have been enormous enthusiasm from many quarters in being the people to solve the structure?
Johann Deisenhofer: You mean inside the Institute?
Yes, inside the Institute?
Johann Deisenhofer: It was not quite that way I don't think so. How do I say that, I mean people, the colleagues of my seniority seemed to think twice about joining such a project. In retrospect, I don't understand that anymore, but at that time it was not that everybody wanted to be the one.
It all moved quite rapidly at that point and you've written before about the fact that you were deeply excited to be involved with it and so excited that you couldn't even sleep. Can you describe how it felt to reveal this structure?
Johann Deisenhofer: There's one point in every structure determination when you can see the general idea of the protein. In this case the biggest question was how are the chromofores arranged in this protein? It has four chlorophylls, two chlorophyll derivatives and heme groups and iron and quinones and it has lots of those and the task of the protein is to keep these in the right geometrical arrangement so that the electronic properties follow from this. That was the most exciting point when I recognised in the electron distribution the chlorophylls and I immediately got hold of some models of, I mean atomic coordinates of chlorophyll molecules, and fit them in and it was very clear that that was correct.
What was the biggest surprise about the structure for you?
Johann Deisenhofer: Its symmetry. It was known from spectroscopic experiments that there was a, known is perhaps not the right way to say it, but some people proposed that there was a pair of chlorophylls in close contact and then there was a so called pheo-phytin that was the acceptor of the electron.
But only one and then a quinone and then a second quinone and there were all kinds of models out there in the literature that accounted for the pair and the pheo-phytin and the quinone and the second quinone but when we looked at the structure it was clear that there were two branches of chlorophylls and pheo-phytins that looked to the naked eye almost identical. They're not identical they're subtle differences in distance and in the protein environment but everybody was speechless at first about the symmetry.
And you trusted your structure determination above any of the previous evidence yes?
Johann Deisenhofer: Yes. The electron density is obtained without any previous hypothesis. I mean you cannot manipulate the /- - -/ information of 50,000 reflections such that they wrongly produce a picture that come from your own preconception, that is impossible, luckily, so there was not always easy to convince more senior scientists that, I mean it's not our fault that this protein has a symmetry. They all thought we had made it up to make it more, or may in their hearts they thought then it was never really said but it took quite a while for the whole field to realise that they have to live with the symmetric reaction centre.
Nowadays of course there have been cases of wrong structural assignment but that's based on the programmes that people are using to convert the data.
Johann Deisenhofer: Yes.
Those didn't exist when you were doing these experiments and therefore that wasn't a potential problem?
Johann Deisenhofer: The example you mentioned indeed came from a piece of software the apparently was never really carefully checked and it caused us a severe kink in a bright young scientist's career yes. But it could have happened to us too but it didn't.
End of story yes. And having determined the structure of the reaction centre then you and your group moved centre stage. Was that hard to deal with?
Johann Deisenhofer: Yes it was. It meant a difference in my way of working and in my lifestyle, because before that I went perhaps to two meetings per year and after the structure came out and it became known that we had a structure, we were inundated with invitations. So there was one year when I travelled to the States six times and it was really amazing how much interest that structure created.
And the most peculiar meeting was in a hotel near the Pentagon which apparently was organised by the Department of Defence and they were at that time trying to think about molecular electronics, and they thought Well, this is indeed a prime example of molecular electronics and there were these four star generals. It was a little strange yes and especially the selection of talks was very, very unusual. I mean there were some talks that were about things that maybe 200 years in the future or something that sort. It was more science fiction than science but I mention this only as an example.
Yes sure. Did you get anything out that meeting in particular?
Johann Deisenhofer: No.
A trip to the Pentagon yes.
Johann Deisenhofer: Not really. No.
So this period of activity culminated in your decision to move away from Germany and come to Dallas which was quite a major move. What brought you to Dallas? Why did you choose this place?
Johann Deisenhofer: After my PhD I thought I might, and because at that time the situation of protein crystallography was not particularly good because this was pre recombinant DNA technology and the proteins were hard to get. The whole field stagnated for a while and the opportunities for young people. So I stayed at the Max Planck and I ... for quite a while I was prepared to spend my whole career there and then came this success story and I was asked many times Would you look at the position at this institution, that institution. I seriously looked at two places in Germany and one of them was the EMBL had as a consequence that somebody at UT Southwestern got the news that I was looking for a job.
And so, out of the blue sky came a letter would you like to visit and look at the possibility to join the faculty and I did some research because I had no clue, it was called UT Health Science Centre at Dallas at the time. I had no clue but I got very good recommendations from people, especially a colleague who did his PhD in Houston and he knew quite a lot about UT Southwestern, so I decided to visit and there was a very stark contrast between the way recruiting is done here and how it is done in Germany. It's essentially going from a seller's market to a buyer's market and that impressed me a lot. So I decided to come for a second visit and then got an offer and still to my surprise one evening I pick up the phone and I call the chairman of biochemistry saying Okay I accept.
Seem like yes I'm not going to Heidelberg I'm coming to Dallas.
Johann Deisenhofer: Yes.
It's a major decision.
Johann Deisenhofer: Yes.
And you liked it so much you stayed ever since.
Johann Deisenhofer: Oh yes.
And then what six months or so after you arrived you learnt that you'd been awarded the Nobel Prize which must have pleased Dallas enormously.
Johann Deisenhofer: You bet yes.
Yes cockahoot they must have been. It must also have put strains on you because presumably tremendous number of offers follow from that.
Johann Deisenhofer: Yes.
And you weren't yet quite established here I imagine.
Johann Deisenhofer: It came at a somewhat not so good moment because I was still struggling to get the lab started and they were a little bit behind with renovations and I had no real experience in leading my own group, recruiting people and so on. I had to learn all that and as the Nobel Prize was a gigantic interruption in this process so my lab moved very slowly in the beginning and maybe I lost a year at least but for me it was worth it. I'm not complaining it's just it could have come a year later.
Yes, and a year isn't that much to lose to the Prize, some I think lose more. But clearly you never wavered your obligation was to Dallas having arrived and it was obviously a good situation anyway.
Johann Deisenhofer: I had no reason to complain and there were offers from Germany later but they came a little bit too soon to be really ... I mean I looked at them I felt obliged to really check out my own feelings what would it mean for me to go back and so on, but in my heart I was always more or less decided to stay here and then by that time I was no longer alone. I had met a nice Professor of my group biology whom I married in 1989 and so if the University in Germany don't really know how to recruit people they really want. They have even bigger difficulties to solve the two body problem I mean if a spouse needs a ... and they made very honoured efforts for their circumstances but I think my wife never, even though she's European she's Danish, she never had any enthusiasm. I mean she said Well, if you really want to go I will come along but that's different from saying Yes let's go.
You mentioned the question of learning how to recruit people and building a team. From your experiences of the people who recruited you and your own working methods, what were you looking for and what do you look for in people you bring in to your lab?
Johann Deisenhofer: People who have a clear idea of the general direction they want to go. People who, now I'm talking about postdocs or in some respect also students, people who are willing to use their own head, who are not waiting for me to tell them what to do and who are hard working I mean that's almost ...
It's a given.
Johann Deisenhofer: It's a given, yes, and who have the ability to get along with colleagues. I mean I was not always successful in finding such people. Especially in the beginning I didn't really know what to look for I mean how to find out whether a person is suitable for our environment or not.
And the same challenges I suppose apply to building the Howard Hughes Medical Institute now setting the direction for that and where it should go and what sort of people it needs to recruit.
Johann Deisenhofer: Yes.
It's the same problem on a different scale?
Johann Deisenhofer: It's a different scale yes. I mean the main part of the Howard Hughes Medical Institute is essentially supporting investigators all over the United States and some scientists are in other countries but what they're doing now, their research centre in Janelia Farm is something of that sort. I mean they must find people who can work together and the whole idea of this new institute is to promote collaboration between small groups of scientists and multi-disciplinary approach and all the buzz words that you can hear all the time but essentially it goes down to hiring the right people and that's a big project.
How do you decide now what projects your teams will work on? What are the criteria for deciding what's ...
Johann Deisenhofer: We have an ambition to determine membrane protein structures. From my photosynthetic period let's say, I had a fascination for light interactions with proteins and chromofores and proteins and these two things determine largely what kind of projects we started. In addition to that, in the beginning especially I was looking for, and I felt that I was expected to look for collaboration inside the medical centre and so we did a pretty successful project as one of my colleagues in biochemistry on P450 enzyme but I also found this professor at North Carolina who had one of the pioneers of light driven DNA repair.
We got a structure of the enzyme that does that. And then still from my photosynthetic period I had been showing, for many occasions, maybe 200 times, a slide that showed a reaction centre and cytochrome bc1 complex and it was always in my head to do that. And indeed there was in a very nice collaboration with a colleague in Oklahoma State University who got bc1 complexes from beef heart mitochondria, so several times a year they ground up enormous quantities of beef heart and they got the protein so together with him they got the structure of a bovine bc1 complex. So in this way I tried to build a network of collaborations with people who are interested in other aspects of certain proteins and whose work will be, or was, very much promoted and helped by the knowledge of a structure.
Johann Deisenhofer: So then I think one of the hopes that people at UT Southwestern had when I came was that I would work on the LDL receptor and indeed I think this was the very first protein we got in our hands through the lab of Mike Brown and Joe Goldstein but at that time the method to make this protein was so tedious that it was inhuman to ask someone to do that. It was a huge operation and it ended with a few milligrams and considering how many trials you need to find crystallisation conditions it was just not doable. And then later I found an outstanding postdoc who in long years of work figured out how to crystallise this protein and indeed we got the structure. I think it was published in 2002 and I came in 1988 so you can count the years.
Some projects are slower than others.
Johann Deisenhofer: Yes. Yes.
But your criteria for inclusion of a project in your schedule so to speak is that it has to be something where the revelation of the structure will make a big difference.
Johann Deisenhofer: Oh yes.
To the study of that area.
Johann Deisenhofer: Yes.
It must be nice you can presumable pick and choose across a vast array of potential projects.
Johann Deisenhofer: Yes. It is however true that structure biology has become an extremely successful field and we have an enormous number of colleagues and sometimes competitors and so whenever an interesting protein pops up there are at least three, four, five groups that would like to solve the structure of that so it has become kind of a race against the clock and against ... it was always like that but the races were easier I have the impression than they are now. And often it's only a matter of a month of so if somebody's earlier than the other one gets the papers into a prestigious journal and the other paper goes in the less prestigious journal and the young person who works on it has either a better chance at a good job or a not so good chance and all this has nothing to do with his merit or with ability it's often sheer luck.
It's causing sleepless nights for a very different reason to those that were causing you not sleep in 82, 83 when presumably you weren't particularly worried about people stealing your thunder.
Johann Deisenhofer: No. At that time there was a widespread opinion that one cannot crystallise membrane proteins and even Hartmut's success didn't really convince a lot of people immediately so they were kind of slow to change their opinion. One of the sort of the great old men in photosynthesis, a professor of physics at UC San Diego George Feher by the way, who will receive the Wolf Prize in Chemistry next month, he had tried to start a programme to crystallise a reaction centre, a different one than we used. When he applied for grant money he was sort of, I mean in an almost insulting way, told that doesn't he know that you cannot crystallise.
The good news about Max Planck was of course that there was not such committee or no wise cracks, so we then had to justify we just had to do it. They tried anyway, but it turned out that their type of reaction centre was more difficult to crystallise than ours. At that time when we worked on it I didn't know. The more dangerous competitor was probably a pair of people who worked on bacterial pouring proteins, Jürg Rosenbush and Mike Garavito in Basel, and it was renowned that they had crystals, but these crystals were of a nasty variety. They had a very complicated form of symmetry where you couldn't really always distinguish between what is a crystallographic and what is local symmetry and so that held them up quite substantially, otherwise they could have been the first ones to present a membrane protein structure.
However, then the view of membrane proteins would have been turned on its head because that protein is all made of beta-sheet and it's an outer membrane protein and they turn out to be all beta-sheet or most of them whereas the inner membrane proteins and the sideroblastic membrane proteins in humans for example they're all /- - -/
So it could have thrown people on the wrong track for a while?
Johann Deisenhofer: Yes. It would have created a sort of not quite correct picture of membrane proteins so these were the competitors we knew about, but our project could hardly have gone any faster than it did. Perhaps nowadays of course it would go much faster because we would have a different technology that collect data and we would synchrotron radiation. We had that at that time also but it was still a wilderness trip to go to synchrotron.
In general the field of structural biology is, do you think, well equipped from all directions or are there things that the field lacks. Other people that should be coming into it.
Johann Deisenhofer: It was always my belief that eventually we have to be able to calculate structures. There is no unknown natural law that still has to be discovered to understand the folding of protein. It's just a complexity and going through the pains of expressing proteins and getting misfolded samples and aggregates. Until you find a way to get them all as native form of protein, all that shouldn't really be necessary in perpetuity. It is just I think, structure biology is a sort of a way to get information until we are at a point where we can really reliably calculate and that point still seems to be not so close.
It gets closer every year, people make astonishing progress in some areas and one of the methods that were proposed is based on the fact that most likely there are only unlimited number of different ways a protein can fold, and if you have an example of every one of those and you have a method to assign your protein of interest to one of the fold types then you should be able to have a significant head start to predict the structure of the unknown protein. That is the ideological basis for structure genomics as the NIH is supporting it. But I have in mind and this is certainly a very important initiative, I don't think it has really had large impact yet or the impact of closing the white areas in the protein fold space but it is an interesting experiment to get hold of as many unknown fold types or as yet undetermined fold type.
So staying with the theme of structural biology for a while, do you think that the discipline itself and indeed the way that structural biologists are contributing, is changing?
Johann Deisenhofer: Yes I think so. When I was young it was a very young discipline still and you could still fit all the protein crystallographers into the ballroom of a small Austrian village which happened actually, yes. But nowadays the field has become very, very large. We talked about the structural genomics and I have the feeling that the job description of structural biologists changes, that institution who hire new faculty, new researchers look for people with a lot broader perspective than just, let's say, crystallography. On the other hand crystallography the methods have been streamlined to an extent that one doesn't need to know much anymore. So I'm talking about computer programmes, I'm talking about data collection facilities at the synchrotrons.
The number of synchrotrons has increased and essentially we will soon be at that point where we send the crystals by mail and get data back through the Internet. This opens of course a certain risk that, I mean, crystallography's still a complicated subject and on the other hand, if you can't follow, you can go through the motion and get a structure. There will be cases in which people who are not experts go through the motions and think they get a structure, or the computer offers them a structure but it may not be the right one. So at South-Western we have tried to start an initiative with a core facility where well trained expert crystallographers offer their collaboration to anybody who's interested. They provide training and in the essence they provide expertise and a reasonable assurance that all the necessary precautions have been followed to exclude the possibility of wrong structures and so on. So I think that could be a very popular model actually. Of course you have to find the right people. As far as people who are doing their individual research projects, I think, as I said before, there will be more and more requirements for much broader approach to biological problems then just one technique.
So the problem with providing structures as a kind of service industry in the same way as you might provide DNA sequencing or something is that once you have the structure that isn't really it. You need to understand more about the derivation and, so it has to be a collaboration, it can't be a provision? And these structural biologists gathered in the ballroom in an Austrian village which is a beautifully European conception, they were crystallographers pure and simple?
Johann Deisenhofer: Yes. I mean they were, at that time crystallography was the most difficult part of protein structure determination. I mean you had to be a computer programmer, you had to be skilful with your hands, and you had to be very, very careful to keep track of what measurements you made and so on. I mean, as I said before, the computers were a huge bottleneck so you really had to know a lot about crystallography to do that job and the people I mentioned in the ballroom many of them were physicists, some chemists Max Perutz was a chemist and you could clearly see from where they came from. I mean do you know Michael Rossmann. Michael Rossmann was obviously a physicist and he was into developing computation methods.
I think of the portrait of Dorothy Hodgkin that's well known of her pouring over a structure with multiple hands and captivating ...
Johann Deisenhofer: That problem came about because the structures were so big that it was very hard to grasp the essence of a structure so people had to work on their projects a lot longer. If you imagine that there was no interactive graphics, so it was, I mean the result was a thing built from either plastic or metal parts and very fragile and easily deformed and many, many person hours put into constructing it and so on.
But if you've constructed it you understand it fully.
Johann Deisenhofer: That's not, no, I don't think so no. Because in essence, proteins are mobile machines. I mean either in an ideal case that just sent electrons around but most enzymes are required to be flexible and what you get is a sort of a single shot out of a movie basically and you have to use your imagination to imagine the rest of the movie basically. So that I don't think comes from, I mean it doesn't come when you built a model.
So ideally what sort of people would you see coming into structural biology now? You've mentioned already that they should be theoreticians working on folding problems, but you also indicated that one still needs to be essentially a crystallographer first and foremost?
Johann Deisenhofer: Well if I said that I didn't really mean it because ...
I probably interpreted.
Johann Deisenhofer: What I meant is crystallography is becoming a technique like many others and it is yet so elaborate that every institution must have at least a few people who really understand. But the projects can be fed in by many others and if I mentioned the fact that I think the people in my lab, they work more than 95% of their time. Not with the x-ray machine but with incubators and shakers and PCR machines and stuff to get the protein and that is really the biggest change in the whole field that to get, I mean all the easy crystals obviously most of them have already been grown and the structure determined and the things we are trying now, I mean the time when a crystal in our lab let's say bigger than a tenth of a milometer is long past I mean.
Compared with what size for the crystals ...?
Johann Deisenhofer: When I joined Hoover's group in 1971 I was very disappointed that the crystal was slightly under a millimetre and that means a factor of 1,000 in volume. Because in my physics time I was working with ruby crystals which you could buy and you could specify the size and so we often used 10 by 10 by 20 millimetres or so just to make them easy to handle. One can say through my career I have used smaller and smaller crystals and at some point the whole thing must end at a single molecule but that of course is the dream of the people who want to build the free electron lasers and the, I mean, extremely powerful next generation of synchrotrons and I don't know whether I will live long enough to see that.
It's a nice dream to hold though. The last thing I think that I'd like to ask you about is to return to the question of what the Nobel Prize meant for your work and indeed your life outside of work. You've mentioned that there was a slight hiccup in research productivity. In terms of benefit, what do you see as the most tangible benefits of the Prize?
Johann Deisenhofer: There were two let's say categories of benefit. One funding and the other one on my internal attitude towards work and towards science and if I start with the latter I really could, I was much more relaxed. After the whole ballyhoo had died down I was much more relaxed than I was as an obscure researcher because I could tell myself, well if I accomplish any more the rest of my life, at least I've done something quite /- - -/ so that was good. And funding was of course easier to come by. It has a definite affect. People don't like to say no to Nobel Laureates so easily. I mean they do but ...
It's harder yes?
Johann Deisenhofer: Yes.
Yes because you mentioned that there were no financial pressures when you were working at the MPI that, for instance, nobody was going to turn around and say, you can't crystallise membrane proteins, so you can't do that project. And that free funding environment must be very liberating?
Johann Deisenhofer: Yes it is but of course, in principle there could have been the Hartmut Michel's boss or my boss and we could not have done much about it. And I would say it's not necessarily unlimited the funding in Max Planck. It looks great but on the other hand the groups are much larger and I think less streamlined than the research groups in America and so the groups in Max Planck they tend to become, or at least some of them in Martinsried tended to become worlds of their own, I mean independent, and they became reluctant to interact with others and so on and here we don't have the money to maintain a group of 50 and it would be an enormous nightmare for me if I had, I mean so I'm perfectly fine with a much smaller group and more interactions with colleagues.
How big do you keep your group?
Johann Deisenhofer: Right now it is 10, 11 yes.
That's about the right size for you?
Johann Deisenhofer: I think so.
Well, it's been marvellous speaking with you thank you very much indeed for taking the time.
Johann Deisenhofer: My pleasure.
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