[Study of crystals of aspartate aminotransferase complexed with D-aspartate].
We report here the first X-ray studies of the complex of cytosolic aspartate aminotransferase from chicken heart with D-aspartate at 2.5 A resolution. Crystals of the complex were grown by cocrystallization (space group is P2(1)2(1)2(1), parameters: a = 62.48 A, b = 117.71 A, c = 124.38 A). They contain one dimeric molecule in the asymmetric unit. The X-ray analysis proves that attachment of D-aspartate induces considerable conformational changes in the active sites of two subunits of the enzyme: both subunits of the complex are in the closed conformation, the interaction of the enzyme with D-aspartate induces a substantial turn (about 90 degrees) of the coenzyme in one subunit, the coenzyme ring is deformed, considerable conformational changes are determined for Phe-18 and Glu-141. Apparently, the amino group of the substrate is a trigger of the conformational changes in the active site of the enzyme.
Kochkina
V M
VM
Korolev
S V
SV
Meador
W E
WE
Wilson
D
D
Quiocho
F A
FA
Kuzin
A P
AP
D000818:Animals; D001219:Aspartate Aminotransferases / Q000737:chemistry*; D001224:Aspartic Acid / Q000737:chemistry*; D001665:Binding Sites; D002645:Chickens; D018360:Crystallography, X-Ray; D003600:Cytosol / Q000201:enzymology; D009206:Myocardium / Q000201:enzymology; D011487:Protein Conformation
D001224:Aspartic Acid; D001219:Aspartate Aminotransferases
Issledovanie kristallov kompleksa aspartat-aminotransferazy s D-aspartatom.