Elongation factor Ts from Thermus thermophilus-- overproduction in Escherichia coli, quaternary structure and interaction with elongation factor Tu.
Article Details
- CitationCopy to clipboard
Blank J, Nock S, Kreutzer R, Sprinzl M
Elongation factor Ts from Thermus thermophilus-- overproduction in Escherichia coli, quaternary structure and interaction with elongation factor Tu.
Eur J Biochem. 1996 Feb 15;236(1):222-7.
- PubMed ID
- 8617268 [ View in PubMed]
- Abstract
The gene encoding the elongation factor Ts from Thermus thermophilus was sequenced, cloned and the protein overproduced in Escherichia coli. In comparison to the EF-Ts from E. coli with 282 amino acid residues, EF-Ts from T. thermophilus is considerably shorter, differing by 86 amino acids. EF-Ts from the thermophile is stable at high temperatures, which facilitates its separation from E. coli proteins. Purified T. thermophilus EF-Ts forms a homodimer with a disulfide bridge between the two cysteine residues at position 190. The modification of Cys19O by iodoacetamide affects neither the dimerization nor the ability of EF-Ts to facilitate the nucleotide exchange of elongation factor Tu. The disulfide bridge was detected only in purified EF-TS, but not in protein extracts immediately after cell disruption. The physiological role of this disulfide bridge remains, therefore, unclear. Besides the quaternary (EF-TU . EF-Ts)2 complex, a ternary EF-TU . EF-Ts2 complex was detected by gel permeation chromatography and polyacrylamide gel electrophoresis. Trypsin cleavage after Lys48 or modification of Cys78 yield inactive EF-Ts, that does not bind to EF-Tu but is still capable of forming homodimers.