Sulfuryl transfer catalyzed by phosphokinases.
Adenosine 5'-sulfatopyrophosphate is a substrate for nucleoside diphosphate kinase. The reaction appears to proceed through a ping-pong mechanism analogous to the physiological reaction involving ATP, presumably by way of a sulfohistidine intermediate. Unlike the phosphoryl transfer reactions, the corresponding sulfuryl transfers catalyzed by nucleoside diphosphate kinase do not have a strict divalent metal requirement. The estimated rate constants for the metal- and nonmetal-catalyzed sulfuryl transfers differ by less than an order of magnitude and are approximately 1000-fold slower than the corresponding phosphate transfers. These results suggest that the role of the metal ion in nucleoside diphosphate kinase is to coordinate the alpha, beta-phosphates of the substrate. Sulfuryl and phosphoryl transfer probably occur through dissociative transition states.
Peliska
J A
JA
Department of Chemistry, University of Wisconsin, Madison 53706.
O'Leary
M H
MH
D000250:Adenosine Phosphosulfate / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport; D002352:Carrier Proteins / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D009701:Nucleoside-Diphosphate Kinase / Q000378:metabolism*; D028044:Phosphate-Binding Proteins; D010710:Phosphates / Q000378:metabolism; D010759:Phosphorus Isotopes; D010770:Phosphotransferases / Q000378:metabolism*; D017853:Phosphotransferases (Alcohol Group Acceptor); D013379:Substrate Specificity
D002352:Carrier Proteins; D028044:Phosphate-Binding Proteins; D010710:Phosphates; D010759:Phosphorus Isotopes; D000250:Adenosine Phosphosulfate; D010770:Phosphotransferases; D017853:Phosphotransferases (Alcohol Group Acceptor); C019617:adenylylsulfate kinase; D009701:Nucleoside-Diphosphate Kinase