After the discovery of the DNA double helix and his return to the United States, Watson turned to study the structure of ribonucleic
acid (RNA), the single-stranded companion molecule to DNA which he and Crick recognized to be the key intermediary in protein
synthesis. Watson here reported his first measurements of the dimensions of the RNA molecule and speculated that it might
be a helix, but admitted that resolving the structure of RNA "is obviously a much tougher puzzle than DNA" (p.2).
Item is handwritten.
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1954-03-28 (March 28, 1954)
Watson, James D.
Original Repository: Wellcome Library for the History and Understanding of Medicine. Francis Harry Compton Crick Papers
I enclose a copy of a note to "Nature" which I have asked Max to send to Gale. It is straightforward and not exciting
but I feel its best we publish the basic data instead of someone else. We have not presented our data from the fibre diagrams
since our pictures remain messy despite effort and we are still unable to resolve the inner rings neatly. What we have so
far looks like the below [diagrams]
In some ways the pictures are remarkably similar to DNA, though obviously different in several points. I would definitely
guess toward a similar structure if the base pairs existed in the plant viruses and despite this difficulty still do so.
Nevertheless we have considered single strand helices of various types. The prettiest of these (found by Alex) has a sugar
phosphate core, a pitch of 4.3 angstroms, 2.15 residues per turn which is held together by hydrogen bonds from position 2
on the sugar to one of the phosphate oxygens. It is neat and compact and I think quite wrong, because of its failure to account
for the wet picture. I suspect that the 12 angstrom reflexion [sic] arises from the pitch and so we are back toward a DNA
like structure without having any
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solid idea how to build one (we are now even imagining branches!). The whole thing is puzzling and paradoxical (for could
DNA be wrong) and is slowly driving me to despair and to loath nucleic acids. Better pictures will obviously help, a clever
idea even more. Leslie Orgel is also interested in solving mess and so occassionally [sic] is Dick Feynmann [sic] but so far
we are impotent.
I am now in a mood to write up the fibre diagrams and to present paradox will probably do so this coming week to show you
in Oak Ridge.
Concerning Oak Ridge: (1) I have no worthwhile ideas about recombination -- will possibly give a talk underlining difficulties
at present extrapolating from our structure -- very funny turnover data -- possibilities of chain breakage, etc.
Am not sure of where I shall stay in Washington -- Possibly Cosmos Club if they are not filled with Academy members. Will
probably arrive on Saturday or early Sunday and leave on Tuesday. Am meeting Hu in either Washington or afterwards in Philadelphia
or New York. I shall possibly drive to Vassar on Saturday for a days vacation from science. It is thus best if we could talk
in quiet between Oak Ridge and Washington. Some friends from Urbana plan to go into the mountains near Oak Ridge for a day
or so after the meetings. Why don't we join them and afterwards fly from Knoxville to Washington (Saturday?).
I shall leave here on Thursday April 15th and stay 2 days at home before going to Urbana on Saturday and driving from there
to Oak Ridge on Sunday.
Am quite anxious to talk with you. Alex is not interested in really understanding picture and Leslie is not a crystallographer.
It is obviously a much tougher puzzle than DNA.
P.S. Congratulations on daughter name? --Am sorry that Sebastian Thumpington Crick is not yet possible -- is it Adenine Crick?