The amino-terminal 118 amino acids of Escherichia coli trigger factor constitute a domain that is necessary and sufficient for binding to ribosomes.
Escherichia coli trigger factor has prolyl-isomerase and chaperone activities and associates with nascent polypeptide chains. Trigger factor has a binding site on ribosomes, which is a prerequisite for its efficient association with nascent chains and its proposed function as a cotranslational folding catalyst. We set out to identify the domain of trigger factor that mediates ribosome binding. Of a series of recombinant fragments, the amino-terminal fragments, TF (1-144) and TF (1-247), cofractionated with ribosomes from cell extracts and rebound to isolated ribosomes in vitro. They competed efficiently with full-length trigger factor for stoichiometric binding to a single site on the large ribosomal subunit. However, TF (1-144) and TF (1-247) differed from full-length trigger factor in that their association with ribosomes was not strengthened by the presence of nascent chains, indicating a role for carboxyl-terminal trigger factor segment in sensing the translational status. The domain responsible for ribosome binding was further investigated by limited proteolysis of recombinant fragments. A stable domain comprising the amino-terminal 118 residues was identified that was still capable of ribosome binding and thus represents a novel structural and functional element of trigger factor.[1]References
- The amino-terminal 118 amino acids of Escherichia coli trigger factor constitute a domain that is necessary and sufficient for binding to ribosomes. Hesterkamp, T., Deuerling, E., Bukau, B. J. Biol. Chem. (1997) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg
