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Manuscripts & Correspondence – Mark Bretscher

Origins of the Contents:

The MRC Unit moved out of the Cavendish Laboratory to the new LMB site in early 1962. Some weeks after that Hans Boye, a Danish research student, and I decided to visit our old haunts. We removed two red name-plates as souvenirs: one from the “Hut” (which Hans Boye took) and that from the “Green House”, which I took. In the open Hut, detritus was everywhere: I took a file (labelled “Protein Synthesis” in Francis’s handwriting) and six posters lying about. The file remained more or less forgotten in my filing cabinet until around 2004. These documents have been deposited in the Archive Centre, Churchill College, Cambridge.

In 1964, Francis holidayed in Hawaii and sent the Molecular Genetics Division a postcard; this was put up on the notice board for about three weeks and then I saved it.

In the early 1980s I found a green file used for keeping laboratory notes in our communal coffee room. This contained many loose sheets of paper and some experiments in Francis’s handwriting. This file I put in my filing cabinet and forgot about until around 2005. On inspection, it contained all the crosses and notes of his experiments with the acridine mutants. This file has also been deposited in the Archive Centre, Churchill College, Cambridge.

A letter dated “May 13, 2003” in reply to me. I had asked him about the use of the C2 symmetry evidence in building the model of DNA. At the 2003 50th anniversary celebrations, Jim had suggested to me that this evidence was not used for constructing the model: its significance only came later, thus helping to give him and Francis greater confidence in the structure proposed. I put this to Francis and this was his reply.

Contents of the “Protein Synthesis” file:

  1. Preface (pdf, 1.7MB) and first chapter (pdf, 3.7MB) of Francis’ thesis, in pencil.
  2. Note in pencil by Jim: (pdf, 104KB) “8.30 am Friday Could you tell Julian Sturtevant that I had to go to London so unable to play squash. Jim” Below this, calculations in biro by Francis.
  3. Draft of paper by Francis, (pdf, 2.6MB) in ink, “Isomorphous replacement. Criteria for sign determination” ~14 pages plus letters from David (Blow) (pdf, 1.5MB) dated 2.1.57 and 29.4.58
  4. “Summary. The structure of Nucleic Acids and related substances”. Draft in pen by Francis (pdf, 2.7MB).
  5. “Short note on genetic RNA” by Francis; (pdf, 1.8MB) ~ 14 pages in pen (presaging mRNA; must be 1959-60.)
  6. A typed copy of “On Protein Synthesis” (pdf, 8.3MB) for the Society of Experimental Biology 1958, with many ink or typed corrections of additions/deletions.
  7. Typed and journal-edited copy of “Theory of Mutagenesis” (pdf, 2.6MB) published in JMB in1960.
  8. Reprint “Protein Interactions” by Linus Pauling. Inscribed “To Dr Crick with the compliments of the author”. Not reproduced.

Six cardboard poster sheets:

  1. A large sheet, about ~70×100 cms, with the structure of an AT pair drawn to scale of unknown date. On edge has two numbers in Crick’s handwriting. Not reproduced.
  2. A smaller sheet, ~50×65 cms, with the projection of the backbone of a ribonucleotide in a helix drawn with measurements of the distances of the atoms from the helix centre. Additional calculations around the perimeter and one of the repeat distances ringed in green and labelled “bad”. All in Crick’s handwriting. Aaron Klug told me it was a projection of the poly A helix, which must date it from ~1960 and used to check a model that had been built. A statement to this effect has been added on the back by Aaron Klug in 2005. This item may be the only exsisting experimental work from Crick’s model building days. Not reproduced.
  3. 4 sheets about the same size as (2.) which depict the structure of DNA. Base pairs, in green and red, are stuck on; there are pictures of the correct pairs and wrong pairs. May date from the 1953 Cold Spring Harbour (CSH) meeting on viruses at which the structure was presented. In 1963 I got Jim Watson to sign one of the base pairs (on sheet 2); I did not have the courage to ask Francis to sign the other one. In 2003 Jim could not remember from whence they came. In “Genes, Girls and Gamow” (2001) Jim states that at the 1953 CSH Symposium, he had brought the “foot-long demonstration model (of the double helix) with the A-T and G-C base pairs colored red and green respectively”. This suggests that these posters were made at about that time although may not have been used at the CSH Symposium.

Green File on the Acridine Mutants.

  • Francis’ experimental notes (pdf, 132KB) on the acridine mutants (probably about 50 leaves in pencil/biro) all dated in 1961. The page shown, “Tuesday 17 Oct 61”, reads, at the bottom:
    L1 and L2 had equal number of wild and small sharp plaques. These are almost certainly the double thus X225 and X146 are -ve therefore coding ratio is 3.

Odile Crick has given her permission for these items to be displayed on this website. They can be copied and used for private study only.

Mark Bretscher, 2006 (Updated 2009)