[Draft of speech given at the International Congress of Biochemistry in Moscow]
The International Congress of Biochemistry in Moscow was held in August 1961. In this typed draft of the classic speech that
pushed Nirenberg into the scientific spotlight, he announces how poly-U amino acids stimulate the incorporation of phenylalanine
into a polypeptide chain. Handwritten corrections are included.
Item is handwritten.
Number of Image Pages:
3 (172,959 Bytes)
ca. August 1961
Nirenberg, Marshall W.
Reproduced with permission of Marshall W. Nirenberg.
Medical Subject Headings (MeSH):
Synthetic RNA and the Poly-U Experiments, 1959-1962
We have obtained a stable, cell-free E. coli system which incorporates C14 amino acids into protein at a rapid rate, which
has many characteristics of protein. Conditions have been found which demonstrate a novel characteristic of this system;
that is, a requirement for messenger or template RNA even in the presence of excess soluble RNA. Naturally occurring RNA
such as C coli messenger RNA and TMV RNA and [ . . . ] synthetic polynucleotide, were active in this system.
First slide, please. Each reaction mixture contains these constitutents in micromoles per milliliter. The enzyme extract
consisted of E. coli ribosomes and 100,000 x g supernatant solution. Complete details are presented in Biochemical and Biophysical
Research Communications 4 (1961).
In slide No. 2, counts per minute per milligram protein is plotted against time and minutes. In the absence of added DNAase,
valine was rapidly incorporated into protein. At the end of 90 minutes
[END PAGE ONE]
[BEGIN PAGE TWO]
The synthetic polynucleotide's polymaleic[?] acid. Addition of microgram[?] qualities of Pol 4 reaction mixtures result
in a 500 to 1000-fold elimination in incorporation of C14-phemyloline into a protein which strongly resembles polyphemyoline[?].
We've tested many other synthetic polynucletudes. Only poly 4 stimulates phenylene [ . . . ].
Randomly mixed polymers of [ . . . ] and were completed [ . . . ]. A solution of ply U and Poly A, which lose pains[?] to
form all and triple stranded felicies[?], had no content[?], whatsoever, suggesting that single -- strandedness is a necessary
requisite for adults[?].
The incorporation is also extremely specific, We've tested every C14 amino acid individually and poly 4 stimulates the
incorporation only of phenylene[?].
[END PAGE TWO]
[BEGIN PAGE THREE]
The mechanism of the incorporation process is under current investigation. Attempts are also being made to determine other
letters of the code.
In summary, a stable, cell-free system has been obtained from E. coli in which incorporation of amino acids into protein was
both [ . . . ] and 100,000 kg [ . . . ] solution were [ . . . ] for [ . . . ]. Phenylene[?] incorporation also[?] required
puromycin, chloramphenicol and Rnase. The product of the reaction was partially characterizing[?] and it appears to be polyphemyoline[?].
These results are in press and will be published shortly in the Power[?] of the Nat [ . . . ]. Poly-U appears to function
in this system as a synthetic template, or messenger RNA. One or more [ . . . ] [ . . . ] [ . . . ], then, appear if [ .
. . ] code for polyphemyoline[?]