National Institutes of Health

. Bethes& 14, Md.

$ Department of HEALTH, EDUCATION, AND WELFARE o Public Health Service

NATIONAL INSTITUTE OF ARTHRITlS AN0 METABOLIC DISEASES
NATIONAL CANCER INSTITUTE
NATIONAL INSTITUTE OF DEKIAL RESEARCH
NATIONAL HEART INSTITUTE
NATIONAL INSTITUTE OF MEMAL HEALTH
NATIONAL uicmmoumuL iNsnm

NATIONAL INSTITUTE OF NEUROL061CAL DlSEASES AND BLINDNESS
THE UIMCN CEMER
DIVISION OF RESEARCH GRANTS

Professor Arthur Kornberg
Department of Microbiology
Washington University

st. Louis, Missouri

Dear Arthur:

I am enclosing two preprints which I am Sure you will find of

interest .

You my recall, last Jurre at tkre EaltLmre meeting, I mentioned

  In the enclosed, you will see that we have observed a reac-

to you the possibility of DN4's acting by forming a three stranded
molecule.
tion between the poly A + rjoly U molecule ( which has a diffraction
pattern very similar to that observed in DNA) and polyuridylic acid,
Apparently, these two oombim in the presence of magnesium ions to form
a three stranded molecule. Furthermore, the reaction appears to be
specific in that the other polynucleotides do not react with the (A + U)
molecule .

This we fSd of great interest because it suggests the

possibility that DNA may act to synthesize RNA by forming single poly-
nucleotide strands in one of the grocnres in DNA.
DNA molecule quite closely, you will see that there are four different
kinds of sites on the molecule.
there are two base pairs each of which my be present in two different
orientations.
the interactions of four incoming ribonucleotides and that they may aot
to synthesize a specific RNA with a specific sequence of bases.

If you look at the

These sites arise from the fact that

It is possible that these four sites are specific for

I hope your DNA synthesis is going along very well.

                                   Have you
passed the region of a 5($ increase in DNA mer that used as primer?
And, have you been able to make enough material to consider the possi-
bility of carrying out X-ray diff'raction studies?

-2-

I ani sure you have read Taylor's work on chromosoms duplication
      It is quite striking and very surprising.

(Jan. 57, PNAS).

With best regards.

Yours sincerely,

Alexander Rich