Defined subcomplexes of the A1 ATPase from the archaeon Methanosarcina mazei Go1:: biochemical properties and redox regulation

The potential A, ATPase genes ahaA, ahaB, ahaC, ahaD, ahaE, ahaF, and ahaG from the anaerobic archaeon Methanosarcina mazei Go1 were overexpressed in Escherichia coli DK8 (pTL2). An A(1) complex was purified to apparent homogeneity and shown by Western blot and N-terminal sequence analyses to contain subunits A, B, C, D, and F but to be devoid of subunits E and G. Further removal of subunit C was without effect on ATPase activity. The enzyme was most active at pH 5.2 and required bisulfite and acetate for maximal activity. Kinetic studies confirmed three new inhibitors for A(1) ATPases (diethylstilbestrol and its derivatives hexestrol and dienestrol) and identified redox modulation as a new type of regulation of archaeal A(1) ATPases. (C) 2003 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All. rights reserved.