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：1981
卷号：78
期号：8
页码：4684-4688
DOI：10.1073/pnas.78.8.4684
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：A segment of DNA containing cya, the gene for adenylate cyclase [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1 ], has been isolated from Salmonella typhimurium. The phage lambda gt4 was used as a cloning vector and adenylate cyclase-positive hybrid phages were isolated that complemented adenylate cyclase-negative bacteria. The cloned DNA fragment encodes a polypeptide of molecular weight 81,000 that gives rise to adenylate cyclase activity. This protein represents a functional mutant of the bacterial adenylate cyclase. When the cya gene was amplified by inserting into a multicopy plasmid, the enzyme activity was overproduced 20-fold, but the cyclic AMP level increased only 60%, suggesting several probable regulatory mechanisms. Overproduction of enzymes by recombinant DNA techniques can be a useful probe of relationships in the metabolizing organism in vivo.
