A Caltech Library Service

A Change from Nonsense to Sense in the Genetic Code

Benzer, Seymour and Champe, Sewell P. (1962) A Change from Nonsense to Sense in the Genetic Code. Proceedings of the National Academy of Sciences of the United States of America, 48 (7). pp. 1114-1121. ISSN 0027-8424.

See Usage Policy.


Use this Persistent URL to link to this item:


For the genetic information in a cistron to be translated into a polypeptide chain each coding unit in the nucleotide sequence must correspond to one of the twenty or so amino acids. If not every possible sequence corresponds to an amino acid, mutations that substitute one base for another could, in certain cases, cause the continuity of the information to be interrupted, and such "nonsense" mutations would block completion of the polypeptide chain. By virtue of a mutant with special properties, it is possible to identify nonsense mutations within the A cistron of the rII region of phage T4. In this paper the criterion for nonsense is applied to certain "ambivalent" rII mutants [1], i.e., ones whose phenotypes can be reversed by suppressor mutations in the bacterial host, Escherichia coli. The results show that an ambivalent mutation that behaves like nonsense in one bacterial host may nevertheless make sense in a second (suppressor containing) host. This suggests that a suppressor mutation in the bacterium can result in addition to the cell's dictionary of a new sensible coding unit, constituting a change in the genetic code of the bacterial cell.

Item Type:Article
Additional Information:Copyright © 1962 by the National Academy of Sciences Communicated May 28, 1962 We wish to thank Mmes. Daine Auzins, Judith Berry, and Barbara Williams for assistance in isolation of the double mutants. This research was supported by grants from the National Science Foundation and the National Institutes of Health.
Record Number:CaltechAUTHORS:BENpnas62
Persistent URL:
Alternative URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:6172
Deposited By: Archive Administrator
Deposited On:27 Nov 2006
Last Modified:14 Nov 2014 19:19

Repository Staff Only: item control page