Analysis of the cya locus of Escherichia coli

Abstract

A 9500-bp DNA segment containing the adenylate cyclase gene ( cya) of Escherichia coli has been isolated and analyzed. Four large proteins are encoded within this fragment — the adenylate cyclase protein (92 kDal), two proteins of unknown function (37 and 32 kDal), and a part of the uvrD-coded protein. Various truncated adenylate cyclase proteins, made from cya genes having as much as 60% of their carboxy-terminal end deleted, are sufficient to complement cya − hosts. When these truncated cya genes are present on a multicopy plasmid in a cya − host, the synthesis of β-galactosidase is still regulated by glucose. The “maxicell” technique was used to visualize the four proteins encoded by this region and some of the truncated adenylate cyclase proteins.