UNIVERSITY OF CAMBRIDGE DEPARTMENT OF PHYSICS
CAVENDISH LABORATORY
Free School Lane,
Cambridge.
14th April 1953
Professor Linus Pauling
Gates & Crellin Laboratory
Pasadena 4, California
U.S.A.
Dear Professor Pauling,
I hope you were not puzzled because we said very little about coiled-coils
when you were here, but your letter to Perutz about them only reached us on the day
after you left.
My recollection of our conversation in the summer is very similar to yours,
except that, as I recall it, it was slightly longer than you have remembered it. In
particular I touched on knobs-into-holes packing and the possibility of a 7-strand
cable. You pointed out to me that this might explain the 27 Å equatorial reflection.
It was natural, therefore, that when Peter told us you were working on coiled-coils
that the idea should get round that I had suggested the idea to you. When your Nature
article was eventually published it was clear to me that there were very little grounds,
if any, for such a belief. In particular you had suggested a definite model, whereas
I had not, and, more important, you had put forward a difference reason for the coiling.
In my view the idea that the α-helix might be inclined is an obvious one,
and it is only a small step from that to the idea of coiling. I attach much more importance
to the reasons underlying the coiling, and the proof that a coiled-coil gives both
5.1 and 1.5 Å reflections on the meridian. On these points we have followed independent
paths.
On reflection I think it might have made things easier if you had let me
know you were writing a paper on the idea, so that I would have had the opportunity
of putting forward my ideas simultaneously. However, as things turned out, thanks
to the many channels of communication between Caltech. and the Cavendish, this is
effectively what happened.
We very much enjoyed your visit here. Watson and I would be most interested
to learn what you feel about our D.N.A. structure when you have had time to digest
the idea and the experimental data.
Yours sincerely,
Francis Crick
