Crystal structure of A3B3 complex of V‐ATPase from Thermus thermophilus |
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| Authors: | Koji Nagata Yoshiko Hori Masasuke Yoshida Shigeyuki Yokoyama So Iwata Ken Yokoyama |
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| Affiliation: | 1. Division of Molecular Biosciences, Imperial College London, South Kensington Campus, London, UK;2. Protein Research Group, Genomic Sciences Center, Yokohama Institute, RIKEN, 1‐7‐22 Suehiro‐cho, Tsurumi‐ku, Yokohama, Japan;3. Chemical Resources Laboratory, Tokyo Institute of Technology, Midori‐ku, Yokohama, Japan;4. ICORP, ATP Synthesis Regulation Project, Japan Science and Technology Agency, National Museum of Emerging Science and Innovation, Koto‐ku, Tokyo, Japan;5. Membrane Protein Laboratory, Diamond Light Source Limited, Harwell Science and Innovation Campus, Chilton, Didcot, Oxfordshire, UK;6. Department of Cell Biology, Faculty of Medicine, Kyoto University, Yoshidakonoe‐cho, Sakyo‐ku, Kyoto, Japan;7. Human Receptor Crystallography Project, Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Agency, Yoshidakonoe‐cho, Sakyo‐ku, Kyoto, Japan |
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| Abstract: | Vacuolar‐type ATPases (V‐ATPases) exist in various cellular membranes of many organisms to regulate physiological processes by controlling the acidic environment. Here, we have determined the crystal structure of the A3B3 subcomplex of V‐ATPase at 2.8 Å resolution. The overall construction of the A3B3 subcomplex is significantly different from that of the α3β3 sub‐domain in FoF1‐ATP synthase, because of the presence of a protruding ‘bulge’ domain feature in the catalytic A subunits. The A3B3 subcomplex structure provides the first molecular insight at the catalytic and non‐catalytic interfaces, which was not possible in the structures of the separate subunits alone. Specifically, in the non‐catalytic interface, the B subunit seems to be incapable of binding ATP, which is a marked difference from the situation indicated by the structure of the FoF1‐ATP synthase. In the catalytic interface, our mutational analysis, on the basis of the A3B3 structure, has highlighted the presence of a cluster composed of key hydrophobic residues, which are essential for ATP hydrolysis by V‐ATPases. |
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| Keywords: | crystal structure FoF1 proton pump rotary motor V‐ATPase |
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