THE LABORATORY OF MOLECULAR BIOLOGY ©

-- PROPOSALS FOR EXTENSION

 

 

1. The Original Plans

When the plans for the present laboratory were submitted-to
Council early in 1958, the main problems to be solved were the
chemical and physical structure of proteins, and the mechanism of
protein synthesis and its genetic control. Accordingly the o |
laboratory was set up with three main divisions, devoted to
Protein Chemistry, Protein Crystallography (since renamed
Structural Studies), and Molecular Genetics. :

‘The first two divisions were to work on the structure of~.
oxygen carriers, enzymes , viruses and muscle. “Tt was hoped that.

. such peseeret would lead to an understanding of biological function
in terms of molecular architecture. The division of Molecular
Genetics - was intended to study the genetic code and its transerip-
tion in ‘protein synthesis, employing the techniques of biochemistry
and genetic fine structure analysis. |

The laboratory was designed, equipped and staffed in accordance |

with these plans.

2. Present Work and Future Developments

(a) Some general points |

 

The laboratory has now been in operation for about 1$ years.
~o7-

All the Divisions are well. sét.up, with substantiak programmes of
work in progress. The re has been aes Orie collaboration between
the Divisions, much facilitated by the canteen, and also some
sharing of apparatus. Joint research programmes between the
Divisions have only recently started, but may be expected to
develop further. |

. “As to facilities, for the four most senior workers the space
and equiment provided was very good. It has, however, proved
inadequate in two respects: . | | | | a

Insufficient space was allowed for Huxley and Klug to build -

Up groups within the Laboratory. Their work, on muscle contraction
and virus eteueture respectively, is going well and deserves to
be expanded. | Both Huxley and Klug have international reputations
and on any assessnent should have more space.
oe The’ space required for chemical work connected with Structural
Studies and Molecular Genetics was also somewhat underestimated.

- We : now come to. consider the future direction of, our research.
“Since o our “laboratory was planned, Molecular Biology has advanced.
rapidly. Many i the initial ‘problems of Molecular Biology are
‘either solved in outline or well on the way to solution, although
in every case much remains to be done. The time has come, there-
fore, to make a reassessment of some of our work. It may seem
surprising that ‘this should be necessary s¢ go soon after the
laboratory has been built, but this is because the. rate of

advance of scientific résearch is becoming almost as fast as the
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rate of planning and erecting new buildings. In the following
pages we wish to. propose moderate expansions of several existing
lines of résearch, two small extensions devoted to enzymatic
function and to the physical chemistry of biological macromole~
cules in solution, and one major new research project concerned

with molecular control mechanisms in cellular development.

(b) Structural Studies and Protein Chemistry

Both these divisions are mainly concerned with the structure
of proteins. When considering the future direction of their
‘research, one is still struck by the extent of our igriorance of
protein structure in general, and by the incompleteness of our
understanding even of the systems which have been most thoroughly
studied.

Thus, despite the great prosress made with the X-ray analyses
of myoglobin and haemoglobin, we still do not understand their
oxygen-combining function and other physiological properties in
terms of molecular structure. No-one has yet solved the structure
of. any enzyme, nor the detailed architecture of any virus.
Huxley's. sliding mechanism of muscular contraction, though undoub—
tedly correct, still has to be explained in chemical and structural
terms. |

On the chemical side, Sanger's aim of developing micro-methods
of amino-acid analysis suitable for application to intracellular
enzymes has been attained as far as the sequence around the active

centre is concerned, but much more remains to be done.
~4-

Therefore, we intend vo continue the refinement of the X-ray
analysis ‘of myoglobin until the positions of all the atoms are
resolved with reasonable accuracy, and ‘the environment of the iron
atom in the presence and absence ae oxygen can: be described in
detail. We should also like to carry the X-ray analysis of.
naciogloBin’ from its present resolution of 6 & to 2 g, which would
give near-atomic resolution. If this could be done for both
oxygenated and deoxygenated haemoglobin, the structural basis of
 hacm-haem interaction and of the Bohr effect could probably be
‘elucidated. We also want to solve the structures of some enzymes
and viruses by ‘both chemical and physical methods, to elucidate
the mechanism of muscular contraction in more detail, and to.
apply electron microscopy to a wider range of problems than at
present.

However, the main object of determining the molecular archi-
tecture of. proteins — is to relate structure to function, not only
for ‘the two oxygen’ carriers, but for some enzymes as well. This
would require kinetic and chemical studies to supplement our X-ray
work. Such studies on myoglobin and haemoglobin have already
-Started on the Continent and in America. We feel that our great
effort on the problem of protein structure should be balanced by
studies on protein function carried out in our own laboratory side
| by side with the structural work. We also feel that our strength
in the X-ray analysis of crystals and in electron microscopy should
be matched by an ability to apply optical and other physical nethods

to the study: of biological macromolecules in solution. |
-~5-

We propose to set up a section for the study of enzyme function
and its relation to molecular structure, probably under Hartley's
direction, and one on the physical chemistry of macromolecules, to
be directed by someone whom we hope to recruit from outside.

We shoulé also like to have some additional space for
biochemical work connected with Structural Studies, for Huxley's
and Klug's work, for building protein models and probably, at some

stage, for housing an electronic computer in the laboratory.

(c) Molecular Genetics and Control Mechanisms

 

_ the classical problems of Molecular Genetics, which comprise
the replication and transcription of the genetic material, the
nature of the genetic code, and the mechanism of protein synthesis,
are now. understood in principle, but many details are still unknown.
For example, the enzymic mechanism of DNA replication, with its
paradoxical problems of uncoiling the parent double helix and coiling
up the two daughter helices, is still obscure. As to the genetic
code, all the evidence agrees that a triplet of nucleotides is”
required to code for one amino acid, but the composition of the
triplets coding for most amino acids is still uncertain, and the
sequence of nucleotides in thein unknown. |

All protein synthesis is now known to be carried out in
small particles of ribonucleoprotein called ribosomes, which hold
the messenger RNA and the nascent polypeptide chain in place.
However, the structure of ribosomes and their exact function in

_ protein synthesis remain to be worked out.
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In summary, it is probably true to say that no major discovery
comparable in importance to that of, say, messenger RNA, now lies.
ahead in this field, but the detailed elucidation of the mechanisms
already discovered is nevertheless vital.

The new major problem in molecular biolo gy is the genetics

 

and biochemistry of control mechanisms in cellular development.
We, propose to start work in this field and gradually make it the
Division's main research.

In the first place, control mechanisms can be studied most
easily in micro-organisms, and this work has already begun. — In.
addition we should like to start exploratory work on one or two
model systems. We have in mind small metazoa, chosen because
they. would be suitable.for rapid genetic and . blochcmical analysis.
Proposals for such work, which we plan.to begin within the next»
few months , are set. out in Appendix I.

Of all the lines of research discussca here, that on control
mechanisms is the most likely one to expand steadily as time goes
on. To develop this work we have the ideal person in Brenner.

It will be recalled that Brenner was recruited in order to baild

up the biochemical and genetical work. His position in the
laboratory is “indispensable, not only because he is the only senior
worker in the laboratory with a biological and medical background,
but because of the unrivalled width of his knowledge, his

. originality and his prodigious out put of ideas and experimental -

results. |
7.

So little is known ‘about control mechanisms that it is
difficult to foretell the way our new work is likely to develop,
but it seems probable that it will be able to lead us to problems
of regulation and ‘differentiation in higher organisms, and
eventually to embryology

‘Stated in molecular terns, one of the central questions is
whether control mechanisms utilize the recognition elements of the
genetic code, i.e. nucleotide triplets coding for the assembly of
amino acid sequences, and represent a specialization of the
translation machinery involved in protein synthesis, or whether
different recognition elements and a different machinery are used.
Therefore, even if the emphasis of the Division's work is to be
shifted to control mechanisms, the present studies on protein
synthesis and the genetic code should be continued, since they
provide the molecular background for the understanding of these

mechanisms,

3. Longer Term ae

 

In the long run Molecular Biology is likely to move towards
and become part of Cell Biology. Until recently, Molecular ‘
Genetics has been mainly concerned with the structure and function
of linear information systems of cells. Its success has made it a
‘subject: central to the understanding of living systems, and we are

| confident that it will continue to hold this position. Cont rol

-mechanisne . and coll recognition and communication must have
~ 8.

molecular bases; therefore the proper direction for Molecular
Genetics, and probably for Molecular Biology as a whole, to take
is towards these more biological problems. We shall then be in a
position to approach them from our molecular viewpoint.

We are fortunate in heving Brenner to direct the work on
control mechanisms. However. it is doubtful if he could take
on these additional problems unaided. A possible arrangement
would be to find 2 new senior person to look after the biochemical
part of the Molecular Genstics Division in place of Tissiéres,.
who kas accepted a post at Geneva, and to create a new Division,
for Cont rol Mechanisms under Brenner. Whatever is eventually
proposed, it will entail space for Brenner's expansion, and we
are in favour of building this now, even if it is not fully

equipped immediately.

4, Optimum size of the Laboratory

It has been said that the present laboratory has reached .
its.optimum size and that collaboration between different groups
will become less likely if it grows any larger. We doubt this.
We want to solve specific problems for which additional space.
and facilities are needed, and it would help, rather than hinder
our work if these could be provided. It has also peen said that
if Brenner, Huxley or Klug wished to expand their activities they
might be better advised to start afresh elsewhere. However, -they
have all refused attractive offers from the United States, where

large departments would have been put at their disposal, because
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they decided that the constellation of people in this laboratory
provided the ideal setting for their research, and because they
hoped that their work, if successful, would be encouraged to
blossom out in England. It is indeed rare to find a group of
senior workers who get along so’ well that they wish to stay
together! We should therefore like to support their plea for
more space, and feel confident that our common interest and
common approach will keep the laboratory together,

A further objection to advising some of. these senior workers
to branch out elsewhere lies in the fact that their work in this.
laboratory and fruitful collaboration between them have only just
-begun. If Klug went elsewhere, there would be no research a
virus structure left here, if Huxley, no research on muscle and no
electron microscopy, if Brenner, no genetics of.micro-organisms.
Thus the departure of each of these workers would amount to the
amputation of a vital limb of Molecular Biology, and would weaken

the laboratory as a whole. |

5. Space provided for senior workers

 

If we define a senior worker as one who holds an appointment
in Senior Grade A or above, there are eleven in the laboratory.
Our total space emount s to 23,000 square feet’, which méans that
the area per senior worker is 2,100 square feet. At the moment
this is somewhat unevenly distributed, and it is fair to say that

Sanger, Crick, Kendrew and I have more space devoted to our own
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interests than Brenner, Huxley, Klug, Harris or Hartley, for
instance, have for theirs. |

It is difficult to state what the optimum space per senior
worker should be, but scientists in similar positions in the
United States appear to have 4,000 to 5,000 square feet of research
apace, and do good work. Offers of appointment which are made
from time to time to senior workers here usually carry a promise of
similar facilities. While we cannot rival these offers, the
proposed expansion is intended to give these men more space and .

facilities: than.they have at present.

6. Additional Space Proposed

 

 

The proposed additions to our research space are set out.
in the table below. Most of the items are self-explanatory; .-
two-need comment.

1.5 Arndt at present has one room of 170 square feet. He
had interesting plans for the design. and construction of new:
devices for recording X-ray diffraction data, but not enough.
space to build them. Since these devices would be extremely
valuable for the X-ray study of proteins and.especially of viruses,
Arndt should be given some additional room. |

.»- 1,10 Uncommitted space. In view of the pace of development
in Molecular Biology, it would be wise to include space not yet
committed to any particular research programme, for unforeseen

future requirements.
-ll-

Appendix II sets out arguments in favour of giving
Dr. L. E. Orgel a section in our laboratory, occupying about
2,000 square fect erode, Since his work, though related to ours,
is not strictly part of it, his case is treated separately from

- the rest.
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1. Net research space, excluding corridors, stairs, etc.

lel
1.2

1.3
1.4
1.5

1.6

1.7
1.8
1.9
1.10
1.11

Brenner (control mechanisms)

Huxley (muscle structure and function; electron
microscope studies of other biological
structures)

Klug (virus structure)
Harris and Hartley (enzyme function)

Arndt (design and construction of X-ray

s

apparatus)

Additional biochemistry for Division of
Structural Studies

Additional space for building protein models
Physical chemistry of biological macromolecules
Space for possible electronic computer
Uncommitted space

Additional storage space

2. For corridors, stairs, etc. add 30%

square feet

2300 V4
980 $

650 3
980 4
330 2

330 2,

490 3
650 4

490 3
2000
1000

 

10200
3000

 

13200

 

 
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APPENDIX I

Differentiation in a Nematode Worm

 

Part of the success of molecular genetics was due to the use of
extremely simple organisms which could be handled in large numbers 3
bacteria and bacterial viruses. The processes of genetic repli-
cation and transcription, of genetic recombination and mutagenesis ,
and the synthesis of enzymes could be studied there in their most
elementary Orn; and, having once been discovered, their appli-
“cability to the higher forms of life could be tested afterwards.

We should “Like +o attack the problem of cellular development in a
similer fashion, chosing the simplest possible differentiated
organism and subjecting it to the analytical methods of microbial
genetics. |

Thus we want a multicellular organism which has a, short life
cycle, can be casily cultivated, and is small enough to be handled
in large numbers, like a micro-organism. It should have relatively
few cells, so that exhaustive studies of lineage and patterns can
be made, and should be amenable to genetic analysis.

We think we have a good candidate in the form of a small
nematode worm, Cacnorhabiditis briggsiae, which has the following
properties. It is a self-fertilizing hermaphrodite, and sexual
propagation is therefore independent of population size. Males
are also found (0.1%), which can fertilize the hermaphrodites,

allowing. stocks to be constructed by genetic crosses. Hach worm
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lays up to 200 eggs which hatch in buffer in 12 hours, producing
larvae 80 in length. These larvae grow to a length of Imm in
33 days, and reach sexual maturity. However, there is no
increase in cell number, only in cell mass. The number of nuclei
| becomes constant at a late stage of development, and divisions
occur only in the germ line. Although the total humber of cells
is only about a thousand, the organism is differentiated and has
an epidermis, intestine, excretory system, nerve and muscle
cells, Reports in the literature describe the approximate .
number of cells as follows: 200 cells in the gut, 200 epidermal
“colts, 60 muscle cells, 200 nerve a The organism normally
feeds on bacteria, but can also be grown in large quantities in
, liver extract broth. It has not yet been grown in a defined
synthetic mediun.

To start with we propose to identify every cell in the worm
and trace lineages. We shall also investigate the constancy of

development and study its genetic control by looking for mutants,
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APPENDIX ITI

Dr. L. E. Orgel

 

 

The position of Dr. Leslie Orgel is a special one and has to
be considered apart from the development of the laboratory.

Orgel has been closely associated with us ever since he came
to Cambridge in 1956. He has followed all our work in detail,
- and in the process has acquired a wide and deep knowledge of
molecular biology. He has written (either alone or in collaboration
with us) ‘several theoretical papers, and is at present engaged on
ca critical. review on the difficult subject of mutagenesis. It is
‘universally recognised that he has one of the keenest intellects
in molecular biology. Moreover, his judgement is good and his
imagination is fertile. If he wished to join us as a theoretician |
(for which he would need very little space) we should give the
proposal our whole-hearted support. a

However, he has made it clear that he wishes to direct certain
experimental work. It has been suggested that this might in some.
way be combined with the direction of the physical chemistry in
the laboratory. Reluctantly we have come to the conclusion that
this is not a good idea, since we feel that although he wishes to
do experiments on some aspects of the physical chemistry of
biological macromolecules, his real interests lie elsewhere.

The problem that attracts his attention above all others is
that of the origin of lifc, and in particular the relatively

Simple chemical reactions which are presumed to have built up the
4g

concentration of small organic molecules needed before life could
begin. He has thought about the se problems for several years, and
has interesting and novel ideas on what experiments should be done.
His wide knowledge of molecular biology, combined with his easy
grasp of theoretical chemistry make him the ideal person for this
work. It would be difficult to match these qualifications anywhere
in the world, and impossible in Great Britain. We have no doubt
that such work, directed by hin, would lead to very interesting
results.

This problem, the origin of life, is not in the same state
as the other lines of work in the laboratory. Rather it recalls
the state of molecular biology at the time the Council first get
“up our Unit. Many interesting things can be tried, but
definitive answers to the main questions are not likely to be
obtained for some time. Moreover, the results will be mainly of ©
"pure" scientific interest, although we are confident that they
will also illuminate molecular biology, and thus, indirectly,
medicine itself.

To support such work is therefore something of a gamble.

We feel, however, that this is the sort of gamble which has to
be taken from time to time, at least in a few well~chosen cases,
if the vitality of the biological: science ia to be preserved.
Moreover, if Orgel does not receive support he will go to the
States, where he will have no difficulty in getting all the
facilities he wants. The loss to British Molecular Biology would

be very great. He is, after all, the youngest F.R.S. in the subject.
-~ 17 -

Although we cannot make a case that this project of Orgel's
is linked closely to our other work, we are vory interested in it.
It is clear that his work should be supported somewhere in
England. We would like him as a colleague and he would like to
work alongside us. The most obvious plan would be to provide
space for him as part of the extension of our laboratory, so that
we should be able to remain in close touch with him. The space

he would require is estimated at 2,000 square feet gross.

M. F. Perutz
FC. #H. C. Crick
od. C. Kendrew

F. Sanger