Open AccessInhibition of Polypeptide Chain Initiation in Escherichia coli by Elongation Factor G
Author(s) -
Sylvia LeeHuang,
Henry Lee,
Severo Ochoa
Publication year - 1974
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.71.8.2928
Subject(s) - translocase , ribosome , biochemistry , aminoacylation , chromosomal translocation , mutant , elongation factor , ef tu , biology , escherichia coli , protein biosynthesis , elongation , rna , chemistry , microbiology and biotechnology , transfer rna , gene , materials science , ultimate tensile strength , metallurgy
We have previously reported the isolation fromE. coli of a specific inhibitor of polypeptide chain initiation that is rendered ineffective when active aminoacylation of transfer RNA is taking place; this is normally the case during natural messenger RNA translation. Surprisingly, the inhibitory activity appears to be a hitherto unrecognized property of the chain elongation factor G. The following hold for preparations purified for either translocase or inhibitor activity: (1 ) equal electrophoretic mobility on polyacrylamide gels; (2 ) equal specific activities for (a ) inhibition of initiation, (b ) translocation, and (c ) ribosome-dependent, uncoupled GTPase; and (3 ) similar heat sensitivity of translocase and inhibitor activities in a temperature-sensitiveE. coli mutant with an altered elongation factor G. Different sites are apparently involved in translocation and inhibition because the former, but not the latter, is sensitive top -chloromercuribenzoate and fusidic acid.