The CyaB protein from Aeromonas hydrophila has been shown to possess adenylyl cyclase activity. While orthologs of this enzyme have been found in some bacteria and archaea, it shows no detectable relationship to the classical nucleotide cyclases. Furthermore, the actual biological functions of these proteins are not clearly understood because they are also present in organisms in which there is no evidence for cyclic nucleotide signaling.
National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA. lakshmin@ncbi.nlm.nih.gov
