Telephone :

Cambridge 48011

1365
MEDICAL RESEARCH COUNCIL APR 5

LABORATORY OF MOLECULAR BIOLOGY,
UNIVERSITY POSTGRADUATE MEDICAL SCHOOL,
HILLS ROAD,
CAMBRIDGE.

2nd April, 1965.

 

Dr. Joshua Lederberg,

Stanford University School of Medicine,
Dept. of Genetics,

300 Pasteur Drive,

Palo Alto, California,

U.S.A.

Dear Josh,

I have not yet seen Holley's paper in Science, but I think
I follow most of what you say.

It is an old speculation that the S-RNA is so big because
it may have to make a rather nicely balanced configurational
change. However, it was assumed that this would come about
when the amino acid was added. Your idea that it will only
happen when the S-RNA combines with the correct codon is new to
me.

Alay

I don't feel that there is anything hard to explain about
the "Bernfield-Nirenberg" binding. You only have to assume that
in addition to the binding energy between the codon and the
anti-codon there is a weak general binding of S-RNA and codon to
the ribosomes. I suspect that the binding between the codon and
the anti-codon without the ribosome is too weak to be observable
at all easily.

Basically I think your idea a good one, but it may be hard
to prove it,
im

[anwe

F. H. C. Crick