Catalytic mechanism of the adenylyl and guanylyl cyclases: Modeling and mutational analysis

摘要

The adenylyl and guanylyl cyclases catalyze the formation of 3',5'-cyclic adenosine or guanosine monophosphate from the corresponding nucleoside 5'-triphosphate. The guany- lyl cyclases, the mammalian adenylyl cyclases, and their micro- bial homologues function as pairs of homologous catalytic do- mains. The crystal structure of the rat type II adenylyl cyclase C_2 catalytic domain was used to model by homology a mammalian adenylyl cyclase C_1-C_2 domain pair, a homodimeric adenylyl cyclase of Dictyostelium discoideum, a heterodimeric soluble gua- nylyl cyclase, and a homodimeric membrane guanylyl cyclase.