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Is there proofreading during polypeptide synthesis?
Author(s) -
Ruusala T.,
Ehrenberg M.,
Kurland C.G.
Publication year - 1982
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1982.tb01240.x
Subject(s) - proofreading , phenylalanine , biology , translation (biology) , transfer rna , ternary complex , leucine , ternary operation , protein biosynthesis , biochemistry , stoichiometry , peptide , stereochemistry , amino acid , rna , chemistry , enzyme , messenger rna , organic chemistry , polymerase , gene , computer science , programming language
The stoichiometric efficiency with which ternary complexes containing Phe‐tRNAphe and Leu‐tRNAleu support polypeptide synthesis has been compared in a poly(U)‐directed, steady‐state translation system. When unfractionated tRNA is used to support synthesis, the number of discharged ternary complexes per peptide bond formed is an average of 48 times greater for leucine than for phenylalanine. When three purified leucine isoacceptor species are tested, they each show a characteristic ratio of ternary complexes discharged per missense insertion, normalized to that for phenylalanine: these are 103, 76, and 45 for Leu‐ tRNA2leu, Leu‐ tRNA3leu, and Leu‐ tRNA4leu, respectively. The data are consistent with the functioning of a proofreading mechanism during translation.