5dn6

Publication Abstract from PubMed

The structure of the intact ATP synthase from the alpha-proteobacterium Paracoccus denitrificans, inhibited by its natural regulatory zeta-protein, has been solved by X-ray crystallography at 4.0 A resolution. The zeta-protein is bound via its N-terminal alpha-helix in a catalytic interface in the F1 domain. The bacterial F1 domain is attached to the membrane domain by peripheral and central stalks. The delta-subunit component of the peripheral stalk binds to the N-terminal regions of two alpha-subunits. The stalk extends via two parallel long alpha-helices, one in each of the related b and b' subunits, down a noncatalytic interface of the F1 domain and interacts in an unspecified way with the a-subunit in the membrane domain. The a-subunit lies close to a ring of 12 c-subunits attached to the central stalk in the F1 domain, and, together, the central stalk and c-ring form the enzyme's rotor. Rotation is driven by the transmembrane proton-motive force, by a mechanism where protons pass through the interface between the a-subunit and c-ring via two half-channels in the a-subunit. These half-channels are probably located in a bundle of four alpha-helices in the a-subunit that are tilted at approximately 30 degrees to the plane of the membrane. Conserved polar residues in the two alpha-helices closest to the c-ring probably line the proton inlet path to an essential carboxyl group in the c-subunit in the proton uptake site and a proton exit path from the proton release site. The structure has provided deep insights into the workings of this extraordinary molecular machine.

Structure of ATP synthase from Paracoccus denitrificans determined by X-ray crystallography at 4.0 A resolution.,Morales-Rios E, Montgomery MG, Leslie AG, Walker JE Proc Natl Acad Sci U S A. 2015 Oct 27;112(43):13231-6. doi:, 10.1073/pnas.1517542112. Epub 2015 Oct 12. PMID:26460036^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.