Characterization and crystallization of a minimal catalytic core domain from mammalian type II adenylyl cyclase.
Adenylyl cyclases play a pivotal role in signal transduction by carrying out the regulated synthesis of cyclic AMP. The nine cloned mammalian adenylyl cyclases all share two conserved regions of sequence, C1 and C2, which are homologous to each other and are together responsible for catalytic activity. Recombinant C1 and C2 domains catalyze the synthesis of cyclic AMP when they are mixed and activated by forskolin, and C2 domains alone also manifest reduced levels of forskolin-stimulated enzyme activity. Using limited proteolysis and mass spectrometry, we have mapped the boundaries of a minimal stable and active C2 catalytic domain to residues 871-1090 of type II adenylyl cyclase. We report the properties and crystallization of this trimmed domain, termed IIC2-delta 4. Crystals belong to space group P4n2(1)2, where n = 1 or 3; a = b = 81.3, and c = 180.5 A; and there are two molecules per asymmetric unit related by an approximate body centering operation. Flash-frozen crystals diffract anisotropically to 2.2 A along the c* direction and to 2.8 A along the a* and b* directions using synchrotron radiation.
Zhang
G
G
Laboratory of Molecular Biology, National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0580, USA.
Liu
Y
Y
Qin
J
J
Vo
B
B
Tang
W J
WJ
Ruoho
A E
AE
Hurley
J H
JH
D000262:Adenylyl Cyclases / Q000737:chemistry*; D000595:Amino Acid Sequence; D000818:Animals; D002384:Catalysis; D003460:Crystallization; D008969:Molecular Sequence Data; D011487:Protein Conformation; D051381:Rats; D014961:X-Ray Diffraction
D000262:Adenylyl Cyclases