TY - JOUR T1 - Structure and conformational states of the bovine mitochondrial ATP synthase by cryo-EM JF - bioRxiv DO - 10.1101/023770 SP - 023770 AU - Anna Zhou AU - Alexis Rohou AU - Daniel G. Schep AU - John V. Bason AU - Martin G. Montgomery AU - John E. Walker AU - Nikolaus Grigorieff AU - John L. Rubinstein Y1 - 2015/01/01 UR - http://biorxiv.org/content/early/2015/10/01/023770.abstract N2 - Adenosine triphosphate (ATP), the chemical energy currency of biology, is synthesized in eukaryotic cells primarily by the mitochondrial ATP synthase. ATP synthases operate by a rotary catalytic mechanism where proton translocation through the membrane-inserted Fo region is coupled to ATP synthesis in the catalytic F1 region via rotation of a central rotor subcomplex. We report here single particle electron cryomicroscopy (cryo-EM) analysis of the bovine mitochondrial ATP synthase. Combining cryo-EM data with bioinformatic analysis allowed us to determine the fold of the a subunit, suggesting a proton translocation path through the Fo region that involves both the a and b subunits. 3D classification of images revealed seven distinct states of the enzyme that show different modes of bending and twisting in the intact ATP synthase. Rotational fluctuations of the c8-ring within the Fo region support a Brownian ratchet mechanism for proton-translocation driven rotation in ATP synthases. ER -