NMR Structures of α-Proteobacterial ATPase-Regulating ζ-Subunits

NMR structures of zeta-subunits, which are recently discovered a-proteobacterial F1F0-ATPase-regulatory proteins representing a Pfam protein family of 246 sequences from 219 species (PF07345), exhibit a four-helix bundle, which is different from all other known F1F0-ATPase inhibitors. Chemical shift mapping reveals a conserved ADP/ATP binding site in zeta-subunit, which mediates long-range conformational changes related to function, as revealed by the structure of the Paracoccus denitrificans zeta-subunit in complex with ADP. These structural data suggest a new mechanism of F1F0-ATPase regulation in alpha-proteobacteria. (C) 2014 Elsevier Ltd. All rights reserved.