3GQB: Crystal Structure Of The A3b3 Complex From V-atpase

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 A resolution. The overall construction of the A(3)B(3) subcomplex is significantly different from that of the alpha(3)beta(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.
PDB ID: 3GQBDownload
MMDB ID: 78301
PDB Deposition Date: 2009/3/24
Updated in MMDB: 2009/12
Experimental Method:
x-ray diffraction
Resolution: 2.8  Å
Source Organism:
Similar Structures:
Biological Unit for 3GQB: dimeric; determined by author and by software (PISA)
Molecular Components in 3GQB
Label Count Molecule
Proteins (2 molecules)
V-type ATP Synthase Alpha Chain(Gene symbol: TTHA1273)
Molecule annotation
V-type ATP Synthase Beta Chain(Gene symbol: TTHA1272)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

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