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Crystal structure of A 3 B 3 complex of V‐ATPase from Thermus thermophilus
Author(s) -
Maher Megan J,
Akimoto Satoru,
Iwata Momi,
Nagata Koji,
Hori Yoshiko,
Yoshida Masasuke,
Yokoyama Shigeyuki,
Iwata So,
Yokoyama Ken
Publication year - 2009
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/emboj.2009.310
Subject(s) - thermus thermophilus , biology , atpase , atp synthase , protein subunit , atp hydrolysis , biochemistry , enzyme , crystal structure , hydrolase , protein structure , crystallography , biophysics , stereochemistry , chemistry , gene , escherichia coli
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 A 3 B 3 subcomplex of V‐ATPase at 2.8 Å resolution. The overall construction of the A 3 B 3 subcomplex is significantly different from that of the α 3 β 3 sub‐domain in F o F 1 ‐ATP synthase, because of the presence of a protruding ‘bulge’ domain feature in the catalytic A subunits. The A 3 B 3 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 F o F 1 ‐ATP synthase. In the catalytic interface, our mutational analysis, on the basis of the A 3 B 3 structure, has highlighted the presence of a cluster composed of key hydrophobic residues, which are essential for ATP hydrolysis by V‐ATPases.