NT.R.,C. Unit,.
10th May;.l?GO, -

Dear Arthur9                 

Many thanksfor the "nearest neighbour" data.   I
wish` I could say that we took onetook at them, and all was
revealed, but in fact w.e have seen no more than is obvious.
That the distribution is not random, but naturally tends
somewhat towards it,  That some differenoes (suoh as that
between AT and TA) &re,consfstent,,but one does notknow
quite what to make 'of them, %'
                                                        i,

  On the,other hand-the b&e-pairing is very satisfactory,
I was very,glad to see that, in your Fed: Proa, note you '     )
stressed that this implies that the chains run in opposite
directions, as this is the only good* piece of evidence in favour
of this feature, apart from the complete X-ray data, and the
interpretation of-that still:leaves much to be desired?   I do
wish I could think of some way to see whether the synthesis goes
inboth directions, _I ' %, .: ,2 ~ :
         : 8                 : _` .',                            ,I
                                                                                               3
  I was most interested to see thatyouhad a G-C polymer9
although I was surprised that it wasn$t GCGC instead of.all G
and ,a11 C. :-. Josh tells me that he thinks your lab, is now
wcontaminatedw with the:AT polymer and that there is really always
at least one primer molecule there!   Do you believe this?   It will
be very interesting to,find how often these systems make tfmistakesff.
I see you have already pushed the rate to below 1 in 1000,
I think Paul Doty',s work is very exciting,   It should open '
the way to a study of recombination ata molecular level.   The
obvious first question is:  can chains.rs+ssort spontaneously (at
a high enough concentration)without heating or is new
needed to.produce reassortment?  :I suspect the latter, synthesis
                                            I still
feel-that $.f,synthesis goes only in one (chemical)edirection this
should produce at least a short stretch of chain which is unpaired
and that this'will beused for recombination.

                                 ',

:'Sydney'and I have'been thinking about the way the genetic
message gets from the gene to the cytoplasm.
working hypothesis: :             We have the following'
                                                     

                                  Continued,.,..


M.R.C. Unit.
10th May, 1$X,

-2-

1,  most of the RNA of ribosomes is not  enetic RNA.
  The genetic RNA may be only 10 to 200 of the total
               7
   ribosomal RNA, "
2,  genetic RNA has the'same base-ratios as the DNA
3.  Genetic RNA is (under some circumstances at least)
  unstable and turns over quickly.

This hypothesis explains .a'number of experiments, but
contradicts others, so we are still J*n two minds about it.
   Since josh was-here.I,have produced the sketch of a
theory of genetic complementation which goes some way to
explaining why oomplementation maps are linear.

  I shall be over. in the AStates for a very,short visit
this June.  I planto attend the Gordon Conference but not
to come West,  However at about the same time Sydney will
be at Cal. Tea, and Leslie Orgel will, be at Stanford, so
you should be able to hear all our news,

With best wishes,

Dr. Arthur 'Kornberg,
Stanford University, 1
School of Medicine,
Dept. of Biochemistry,
STANFORD, California,
U.S.A,