December 6, 1960

Ik. Faith N. Ereruaeman
Department of Biochemistry
Yale Univarsi ty
333 &due Street
New Havern, Connecticut

   Sound8 aa though you wig1 be busy filling out forms for awhile.
I'll try to help Out by suggesting several projects.  You are free to
use olny of the ones mentioned and I would certainly urge you to reud
up some and expand the brief wtlb I will offer when you finally do
write up the upplicatiaae.  Of copIra%, it ia entirely possible that
the outcome of our current work, or your own interests, may change
the final decision when you actually get to work but we needn't womy
about that.

Now for some suggestions.

1.

To study the biosynthesis of 5-ribosyl uracil 5'-phosphate
               We have done an in vivo elcpari-

(also known as pseudouridylic acid).
menr, with growing yeast, showing that the pseudouridyfic in RNA comes
directly from orotic.  An dnrost identical experiment was published by
Hall and Allan, Bioehb. et Biophys. Acta, 39, 557 (1960).  Subsequently,
we spent a fair ammmt: of time trying to germ in vitro system going,
using, primarily, yeast extracts and going m the hunch that the reaction
might be, overall., orotic + PaPP .-) S-ribosylorotic-S'-1aonophosphare
+ PP S-ribosy~rotic-S'-glonophosphate -~5-rLbosyluracfl-S'-~o-
phasphate. We were completely unsuccessful.  One of the problems  is to
work out 8 decant assay for 5-ribosyluracil in the presence of uridylic,
since under our conditions our e%tracts, of course, made a lot of uridylic.
The spectrum of 5-riboeyluracil wae .not sensitive enough, not tha odd
orclnol reaction (for both, see W. Cob, J. Bid. Chem., this sununer
oloPPetirm).
orotic.  It is entirely pos8ible that the reaction is n0t as written
akive.
acid + PP 5-ribosyt-s'-~nophosph4te-5' -uridylic acid -) 5' -pseudo-
uridylic acid.
reaction 2.
uracil derivative chemically, starting with pseudouridine, which is readily
isolable from S-RNA.

Ue finally resorted to paper chromatography and labeled

Hrnt about W -4- PBpP-s S-tibosyl-5'-monophosphate-5'-Jrldylic

This shuuld be looked into, perhaps by starting with

Perhaps we could try our hand at ding that diribose-

Dr. Faith Brenrteman -2-

2.

To atudy kh!ttfcs and mechanism of action of polynucleotide

phosphorylase.
needs to bar done--tliae, the relation between the three reactione, exchange,
polymerization, phsphorolysis.
reaction is fascinating.
done, I'll stop.
lack of a good prepar:at€cm, but I hope this wilt be solwd before ycw
get bra.
rather crude prepaxation which hBs, however, the lwely attribute of
being afmost free of nuclaie acid end has an absolute primer require-
ment.  It should be ready fox chtaflsd mechanism experiment8 when you
get here,
II_ 234, 2965, 997% (3959).
differrant ene)farrtas for different diphosphates.
with one enother and we have n~t been able to repeat his apczcific inhibi-
tions,
other might be mors! Interesting to you.
opportunity to learn tu mako polymersr oligonucleotides, etc.

Ham a look at enclosed reprLnts and 88% how mch really


      Before 1 start to write a book on what's to be

The kinetics of any polymriqation

One of the ohief abstaclecc to doing this has been the

We haver started afresh dth g. lyaoderlktfcus and now have a

the way, look at Olmoted's papere on this an-, J.B.C.,
      Owc data, so far, doe8 not support hfa, idea of

                     Our activities go along

This probbm would probably be amre sure-fire than 81, but the

This WMtld oEfer you the

3.

      Another problem already begun irs th study of 8n Interesting
nuclease in Ehrlich hcitea Tumor. Malcolm Martin, ct third-year Yale
medical crtudent haa worked on this summers, but this coming sumDLBr will
be his lacat and you could take it up.
8 start.
RNA.
by Anderson and Bern1 (see enclosed reprint).
expcsriaente indicating 2t g5ws intereating oligonucleorfdes frm S-RNA
and thEs would be a particular are8 to push,  It: would no doubt get you
into aepnae studkae with S-RMA in
and would be very inetructive as well as a lot of fun.
use acme new column retchniquets for separathg otigonucleoridrss (DUE,
etc.) a& we11 as paper chromatography and elactraphorasie.
epecrific chemical and enzymic procedures for studying the strueturea.
(%e ilappel' B review, enctomd) .

;ct will need more puriftoatton as

Aha, specifScity studies on specific polymers 68 well as on

It S@BW to be: fairly sbiLar eo t?m lsukcaarfa enzyme deecribed

We have eome preliminary

inveatigation of the products

Wa could probably

  Aho, various

When you de a decision let. rtl~a knaw and I'll ewy~ up with me

details.
all works out as we would enjoy having you hare.

&st of luck un the appffcations,

1c certainly hape that this

Your$ $

Enclosures


MS:wEt

Maxine Singer