3i4l
Structural characterization for the nucleotide binding ability of subunit A with AMP-PNP of the A1AO ATP synthaseStructural characterization for the nucleotide binding ability of subunit A with AMP-PNP of the A1AO ATP synthase
Structural highlights
Function[VATA_PYRHO] Produces ATP from ADP in the presence of a proton gradient across the membrane. The archaeal alpha chain is a catalytic subunit. Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe crystal structures of the nucleotide-empty (A(E)), 5'-adenylyl-beta,gamma-imidodiphosphate (A(PNP))-bound, and ADP (A(DP))-bound forms of the catalytic A subunit of the energy producer A(1)A(O) ATP synthase from Pyrococcus horikoshii OT3 have been solved at 2.47 A and 2.4 A resolutions. The structures provide novel features of nucleotide binding and depict the residues involved in the catalysis of the A subunit. In the A(E) form, the phosphate analog SO(4)(2-) binds, via a water molecule, to the phosphate binding loop (P-loop) residue Ser238, which is also involved in the phosphate binding of ADP and 5'-adenylyl-beta,gamma-imidodiphosphate. Together with amino acids Gly234 and Phe236, the serine residue stabilizes the arched P-loop conformation of subunit A, as shown by the 2.4-A structure of the mutant protein S238A in which the P-loop flips into a relaxed state, comparable to the one in catalytic beta subunits of F(1)F(O) ATP synthases. Superposition of the existing P-loop structures of ATPases emphasizes the unique P-loop in subunit A, which is also discussed in the light of an evolutionary P-loop switch in related A(1)A(O) ATP synthases, F(1)F(O) ATP synthases, and vacuolar ATPases and implicates diverse catalytic mechanisms inside these biological motors. Nucleotide binding states of subunit A of the A-ATP synthase and the implication of P-loop switch in evolution.,Kumar A, Manimekalai MS, Balakrishna AM, Jeyakanthan J, Gruber G J Mol Biol. 2010 Feb 19;396(2):301-20. Epub 2009 Nov 26. PMID:19944110[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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