Isolation of a metK mutant with a temperature-sensitive S-adenosylmethionine synthetase.

摘要: An Escherichia coli metK mutant, designated metK110, was isolated among spontaneous ethionine-resistant organisms selected at 42 degrees C. The S-adenosylmethionine synthetase activity of this mutant present lower levels than in the corresponding wild-type strain and more labile enzyme when heated or dialyzed. A mixture preparations had an equal to sum component activities. These facts strongly suggest that mutated gene is structural for enzyme. Genetic mapping experiments placed metK110 mutation near site other known mutants (i.e., 63 min), confirming its designation as a mutant. revised order has been established region, i.e., metC glc speC speB serA.