The class III adenylyl cyclases: multi-purpose signalling modules.
cAMP serves as a second messenger in virtually all organisms. The most wide-spread class of cAMP-generating enzymes are the class III adenylyl cyclases. Most class III adenylyl cyclases are multi-domain proteins. The catalytic domains exclusively work as dimers, catalysis proceeds at the dimer interface, so that both monomers provide catalytic residues to each catalytic center. Inspection of amino acid sequence profiles suggests a division of the class III adenylyl cyclases in to four subclasses, class IIIa-IIId. Genome projects and postgenomic analysis have provided novel aspects in terms of catalysis and regulation. Alterations in the canonical catalytic residues occur in all four subclasses suggesting a plasticity of the catalytic mechanisms. The vast variety of additional, probably regulatory modules found in class III adenylyl cyclases obviously reflects a large collection of regulatory inputs the catalytic domains have adapted to. The large versatility of class III adenylyl cyclase catalytic domains remains a major scientific challenge.
Linder
Jürgen U
JU
Fakultät fur Chemie und Pharmazie, Abteilung Pharmazeutische Biochemie, Pharmazeutisches Institut, Universität Tübingen, Morgenstelle 8, D-72076, Tübingen, Germany. juergen.linder@uni-tuebingen.de
Schultz
Joachim E
JE
D000262:Adenylyl Cyclases / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D020134:Catalytic Domain; D006162:Guanylate Cyclase / Q000235:genetics / Q000378:metabolism; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction
D007527:Isoenzymes; D000262:Adenylyl Cyclases; D006162:Guanylate Cyclase