Adenylosuccinate lyase of Bacillus subtilis regulates the activity of the glutamyl-tRNA synthetase.
In Bacillus subtilis, the glutamyl-tRNA synthetase [L-glutamate:tRNA(Glu) ligase (AMP-forming), EC 6.1.1.17] is copurified with a polypeptide of M(r) 46,000 that influences its affinity for its substrates and increases its thermostability. The gene encoding this regulatory factor was cloned with the aid of a 41-mer oligonucleotide probe corresponding to the amino acid sequence of an NH2-terminal segment of this factor. The nucleotide sequence of this gene and the physical map of the 1475-base-pair fragment on which it was cloned are identical to those of purB, which encodes the adenylosuccinate lyase (adenylosuccinate AMP-lyase, EC 4.3.2.2), an enzyme involved in the de novo synthesis of purines. This gene complements the purB mutation of Escherichia coli JK268, and its presence on a multicopy plasmid behind the trc promoter in the purB- strain gives an adenylosuccinate lyase level comparable to that in wild-type B. subtilis. A complex between the adenylosuccinate lyase and the glutamyl-tRNA synthetase was detected by centrifugation on a density gradient. The interaction between these enzymes may play a role in the coordination of purine metabolism and protein biosynthesis.
Gendron
N
N
Département de Biochimie, Faculté des Sciences et de Génie, Université Laval, Québec, Canada.
Breton
R
R
Champagne
N
N
Lapointe
J
J
D000264:Adenylosuccinate Lyase / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics; D001483:Base Sequence; D002852:Chromatography, Ion Exchange; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D005798:Genes, Bacterial; D005809:Genes, Regulator; D005838:Genotype; D005975:Glutamate-tRNA Ligase / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D008969:Molecular Sequence Data; D009876:Operon
D000264:Adenylosuccinate Lyase; D005975:Glutamate-tRNA Ligase