期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1977
卷号：74
期号：4
页码：1662-1666
DOI：10.1073/pnas.74.4.1662
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The product of a newly identified gene, glnF, which is distinct from the glutamine synthetase structural gene (glnA), is required for synthesis of glutamine synthetase [L-glutamate:ammonia ligase (ADP-forming), EC 6.3.1.2 [ in Salmonella typhimurium and probably in Escherichia coli. Salmonella strains with ICR (2-chloro-6-methoxy-9-[3-(2-chloroethyl)aminopropylamino]acridine dihyodrochloride)-induced (frameshift) mutations in glnF are glutamine auxotrophs; they have less than 10% oof wild-type glutamine synthetase activity or antigen and are unable to derepress the synthesis of the enzyme. The mutant allele is recessive to the wild-type allele, indicating that the glnF gene encodes a diffusible product. Mutant glnF strains have normal activities of all proteins involved in covalent modification of glutamine synthetase: adenylyltransferase (EC 2.7.7.42 ), PII, uridylyltransferase, and uridylyl removing enzyme. In addition, they have glutamate synthase (EC 1.4.1.13 ) and glutamate dehydrogenase (EC 1.4.1.4 ) activities. Thus, glnF does not encode the structure of any of these proteins. The above evidence suggests that the product of the glnF gene is (or produces) a positive regulatory factor that is required for synthesis of glutamine synthetase; it indicates that auto-regulation cannot account for control of the synthesis of glutamine synthetase in Salmonella.
