GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com

PMID:348689

From GONUTS
Jump to: navigation, search
Citation

Williams, AL, Whitfield, SM and Williams, LS (1978) Synthesis and activities of branched-chain aminoacyl-tRNA synthetases in threonine deaminase mutants of Escherichia coli. J. Bacteriol. 134:92-9

Abstract

Valyl-, isoleucyl-, and leucyl-tRNA synthetase activities were examined in an Escherichia coli K-12 strain that possessed a deletion of three genes of the ilv gene cluster, ilvD, A, and C, and in a strain with the same deletion that also carried the lambdadilvCB bacteriophage. It was observed that the branched-chain tRNA synthetase activities of both strains were considerably less than those of the normal strain during growth in unrestricted medium. Furthermore, during an isoleucine limitation, there was a further reduction in isoleucyl-tRNA synthetase activity and an absence of the isoleucine-mediated derepression of valyl-tRNA synthetase formation in both of these mutants, as compared with the normal strain. In addition, it was observed that these branched-chain synthetase activities were reduced in steady-state cultures of several ilvA point mutants. However, upon the introduction of the ilv operon to these ilvA mutants by use of lambda bacteriophage, there was a specific increase in the branched-chain synthetase activities to levels comparable to those of the normal strain. These results support our previous findings that the stability and repression control of synthesis of these synthetases require some product(s) missing in the ilvDAC deletion strain and strongly suggest this component is some form of the ilvA gene product, threonine deaminase.

Links

PubMed PMC222222

Keywords

Amino Acyl-tRNA Synthetases/metabolism; Enzyme Repression; Escherichia coli/enzymology; Escherichia coli/genetics; Genes; Isoleucine/pharmacology; Isoleucine-tRNA Ligase/metabolism; Kinetics; Leucine-tRNA Ligase/metabolism; Threonine Dehydratase/metabolism; Valine-tRNA Ligase/metabolism

Significance

Annotations

Gene product Qualifier GO Term Evidence Code with/from Aspect Extension Notes Status

ECOLI:ILVA

acts_upstream_of_or_within

GO:0009082: branched-chain amino acid biosynthetic process

ECO:0000315: mutant phenotype evidence used in manual assertion

P

Seeded From UniProt

complete

ECOLI:THD1

involved_in

GO:0009082: branched-chain amino acid biosynthetic process

ECO:0000315: mutant phenotype evidence used in manual assertion

P

Seeded From UniProt

complete

See also

References

See Help:References for how to manage references in GONUTS.