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Updated: Aug 17, 2026

Isolation of Translating Ribosomes Containing Peptidyl-tRNAs for Functional and Structural Analyses
Published on: February 25, 2011
A peptide from Tetrahymena disrupts subunit organization of E. coli RNA polymerase
1Department of Biochemistry B, Panum Institute, University of Copenhagen, Denmark.
Abstract:
Incubation of the E. coli RNA polymerase with a polypeptide factor from the protozoan Tetrahymena reduces the affinity of the holoenzyme for DNA. SDS-polyacrylamide gel electrophoresis of the peptide-treated RNA polymerase showed that the band pattern of the polymerase subunits was strongly altered. The three large subunits, beta', beta and sigma, disappear and a high number of rapidly migrating bands appeared. However, a brief heat treatment of the samples almost restored the original RNA polymerase subunit composition, and in addition a high molecular weight protein band approximately 240 kDa appeared. It is suggested that the Tetrahymena peptide specifically binds to the RNA polymerase and changes the structures of the large subunits.
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