NATIONAL INSTITUTE OF GENETICS

YATA 1,117 MISIMA, SIZUOKA-KEN,

411 JAPAN
Y. Hirota

Cable address: Genetics, Misima

June 2, 1976

Professor Joshua Lederberg
Department of Genetics

Stanford University Medical Center
Stanford, California 94304

U. S. A.

Dear Joshua :

Under the separate cover, I am sending you a manuscript of
peptidyl-transferase I (coaboxypeptidase/ transpeptidase/
endopeptidase)-less mutant of E. coli. I am grateful to you if
you could communicate this manuscript to the Proc. Nat. Acad. Sci.,
U.S.A,

As you know, this enzyme have been considered the killing
target of penicillin action, however we present here the negative
evidences against the possibility. Many years ago, you pointed
out the site of penicillin action is specific for the septation
site of cell wall, and I thought that if I could ask your favor
to communicate it?

On my return, I have been continuing my work towards the
problem of cell wall biosynthesis with respects to the cell
growth and cell division of E. coli K12. Because of your
discoveries of penicillin action, I worked out on a penicillin-
targets, and this is becomming my first work done in Japan on
my return.

We have now an other mutant lacking peptidyl transferase II
(Ghuysen-Pollock's peptidoglycan-carboxypeptidase) which grows
normally. Furthermore, a double mutant lucking both defects
was constructed from these mutants. It grew completely happily.
We are now on the way to find the real enzymes responsible for the
cell division and cell wall synthesis: the enzyme reactions which
you predicted about 20 years ago.

Looking forward of your favorable answer, and thank you
very much,in advance.

Sincerely yours,

Miki v
Y/ Hirota ,