Identification of the betaTP site in the x-ray structure of F1-ATPase as the high-affinity catalytic site.

ABSTRACT: ATP synthase uses a unique rotary mechanism to couple ATP synthesis and hydrolysis to transmembrane proton translocation. The F(1) subcomplex has three catalytic nucleotide binding sites, one on each beta subunit, with widely differing affinities for MgATP or MgADP. During rotational catalysis, the sites switch their affinities. The affinity of each site is determined by the position of the central gamma subunit. The site with the highest nucleotide binding affinity is catalytically active. From the available x-ray structures, it is not possible to discern the high-affinity site. Using fluorescence resonance energy transfer between tryptophan residues engineered into gamma and trinitrophenyl nucleotide analogs on the catalytic sites, we were able to determine that the high-affinity site is

SUBMITTER: Mao HZ 

PROVIDER: S-EPMC2141802 | biostudies-literature | 2007 Nov

REPOSITORIES: biostudies-literature