title: Elongation factor Ts from Thermus thermophilus-- overproduction in Escherichia coli, quaternary structure and interaction with elongation factor Tu.
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.
authors.affiliation: Laboratorium für Biochemie, Universität Bayreuth, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Blank
authors.forename: S
authors.initials: S
authors.lastname: Nock
authors.forename: R
authors.initials: R
authors.lastname: Kreutzer
authors.forename: M
authors.initials: M
authors.lastname: Sprinzl
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D008969:Molecular Sequence Data; D010444:Peptide Elongation Factor Tu / Q000378:metabolism; D010445:Peptide Elongation Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D010446:Peptide Fragments; D011485:Protein Binding; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D016963:Thermus thermophilus / Q000737:chemistry / Q000235:genetics*; D014357:Trypsin
chemical_list: D010445:Peptide Elongation Factors; D010446:Peptide Fragments; D011994:Recombinant Proteins; C023512:elongation factor Ts; D014357:Trypsin; D010444:Peptide Elongation Factor Tu