Three-dimensional structure of A1A0 ATP synthase from the hyperthermophilic archaeon Pyrococcus furiosus by electron microscopy

Abstract

The archaeal ATP synthase is a multisubunit complex that consists of a catalytic A1 part and a transmembrane, ion translocation domain A0. The A1A0 complex from the hyperthermophile Pyrococcus furiosus was isolated. Mass analysis of the complex by laser-induced liquid bead ion desorption (LILBID) indicated a size of 730 ± 10 kDa. A three-dimensional map was generated by electron microscopy from negatively stained images. The map at a resolution of 2.3 nm shows the A1 and A0 domain, connected by a central stalk and two peripheral stalks, one of which is connected to A0, and both connected to A1 via prominent knobs. X-ray structures of subunits from related proteins were fitted to the map. On the basis of the fitting and the LILBID analysis, a structural model is presented with the stoichiometry A3B3CDE2FH2ac10. © 2009 by The American Society for Biochemistry and Molecular Biology, Inc.