Plays essential roles in regulation of cellular metabolism by catalyzing the synthesis of a second messenger, cAMP. ATP = 3',5'-cyclic AMP + diphosphate Binds 1 Mg(2+) ion per subunit. In contrast to yeast cyclase, S.pombe cyclase is not likely to be regulated by RAS proteins. Activated by git1. Interacts with git1. Belongs to the adenylyl cyclase class-3 family.