UNIVERSITY OF CAMBRIDGE DEPARTMENT OF PHYSICS
Free School Lane,
14th April 1953
Professor Linus Pauling
Gates & Crellin Laboratory
Pasadena 4, California
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.