Heterotetramer of two alpha and two beta subunits. Paraxonemal body. And paraxonemal bodies (PABs). The FB strain is deficient in phototaxis. It is not known if this is due to defective adenylate cyclase activity or defective BLUF domains in this protein. In wild-type E.gracilis, photoactivated adenylate cyclase is found in the paraxonemal bodies (PABs). PABs are not visible in all cells in this strain, and are smaller than in wild-type. Belongs to the adenylyl cyclase class-4/guanylyl cyclase family.