Preliminary crystallization studies of calmodulin-dependent protein phosphatase (calcineurin) from bovine brain.
Calcineurin is a serine/threonine protein phosphatase which catalyzes the hydrolysis of both phosphoseryl/phosphothreonyl and phosphotyrosyl proteins as well as low molecular weight compounds such as p-nitrophenyl phosphate. It is a hetero-dimeric protein consisting of a 60 kDa A chain and 19 kDa B chain. Calcineurin A is organized into functionally distinct domains such as a catalytic domain, a calcineurin B binding domain, a calmodulin-binding domain, and an inhibitory domain. Calcineurin B has four EF-hand calcium binding domains with a secondary structure that is homologous to calmodulin but its metal binding properties are more similar to troponin-C. The N-terminal myristoyl group of calcineurin B might play a role in the interaction between subunits A and B during phosphorylation/dephosphorylation processes. Crystals of size 0.125 x 0.07 x 0.03 mm and 0.7 x 0.03 x 0.02 mm have been obtained for calcineurin and the A subunit respectively. Crystals of calcineurin show strong diffraction to 5.3 A and weak diffraction to 3.0 A on rotating anode operated at 50 kV and 100 mA. Further work is in progress to improve the X-ray diffraction quality of these crystals and to obtain well diffracting crystals of calcineurin B.
Balendiran
K
K
Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, PA 19140, USA.
Tan
Y
Y
Sharma
R K
RK
Murthy
K H
KH
D000818:Animals; D001921:Brain / Q000201:enzymology; D019703:Calcineurin; D002148:Calmodulin-Binding Proteins / Q000737:chemistry*; D002417:Cattle; D018360:Crystallography, X-Ray; D009682:Magnetic Resonance Spectroscopy; D008667:Metalloproteins / Q000737:chemistry; D010749:Phosphoprotein Phosphatases / Q000737:chemistry*; D017433:Protein Structure, Secondary
D002148:Calmodulin-Binding Proteins; D008667:Metalloproteins; D019703:Calcineurin; D010749:Phosphoprotein Phosphatases