Isolation and characterization of an Escherichia coli seryl-tRNA synthetase mutant with a large increase in Km for serine.
AUTOR(ES)
Willison, J C
RESUMO
A mutant of Escherichia coli resistant to serine hydroxamate which has a large increase in Km for serine of seryl-tRNA synthetase is described. The mutant serS gene was cloned and sequenced and was found to contain a single-base-pair mutation, resulting in the substitution of the residue alanine 262 by valine in motif 2. The methyl side chain of alanine 262 is not exposed at the active site, and molecular modeling indicated that replacement of alanine 262 by valine does not significantly affect the configuration of amino acids at the active site. This finding suggests that the residue at this position may be involved in a conformational change (possibly induced by ATP binding) which is necessary for optimal binding of the cognate amino acid.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=177033Documentos Relacionados
- Characterization of a temperature-sensitive Escherichia coli mutant and revertants with altered seryl-tRNA synthetase activity.
- Cloning and characterization of the gene for Escherichia coli seryl-tRNA synthetase.
- Seryl-tRNA synthetase from Escherichia coli: functional evidence for cross-dimer tRNA binding during aminoacylation.
- Coexpression of eukaryotic tRNASer and yeast seryl-tRNA synthetase leads to functional amber suppression in Escherichia coli.
- Seryl-tRNA synthetase from Escherichia coli: implication of its N-terminal domain in aminoacylation activity and specificity