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Intermediate position of ATP on its trail to the binding pocket inside the subunit B mutant R416W of the energy converter A1Ao ATP synthaseIntermediate position of ATP on its trail to the binding pocket inside the subunit B mutant R416W of the energy converter A1Ao ATP synthase
Structural highlights
FunctionVATB_METMA Produces ATP from ADP in the presence of a proton gradient across the membrane. The archaeal beta chain is a regulatory subunit. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedA strategically placed tryptophan in position of Arg416 was used as an optical probe to monitor adenosine triphosphate and adenosine-diphosphate binding to subunit B of the A(1)A(O) adenosine triphosphate (ATP) synthase from Methanosarcina mazei Go1. Tryptophan fluorescence and fluorescence correlation spectroscopy gave binding constants indicating a preferred binding of ATP over ADP to the protein. The X-ray crystal structure of the R416W mutant protein in the presence of ATP was solved to 2.1 A resolution, showing the substituted Trp-residue inside the predicted adenine-binding pocket. The cocrystallized ATP molecule could be trapped in a so-called transition nucleotide-binding state. The high resolution structure shows the phosphate residues of the ATP near the P-loop region (S150-E158) and its adenine ring forms pi-pi interaction with Phe149. This transition binding position of ATP could be confirmed by tryptophan emission spectra using the subunit B mutant F149W. The trapped ATP position, similar to the one of the binding region of the antibiotic efrapeptin in F(1)F(O) ATP synthases, is discussed in light of a transition nucleotide-binding state of ATP while on its way to the final binding pocket. Finally, the inhibitory effect of efrapeptin C in ATPase activity of a reconstituted A(3)B(3)- and A(3)B(R416W)(3)-subcomplex, composed of subunit A and the B subunit mutant R416W, of the A(1)A(O) ATP synthase is shown. Spectroscopic and crystallographic studies of the mutant R416W give insight into the nucleotide binding traits of subunit B of the A1Ao ATP synthase.,Kumar A, Manimekalai MS, Balakrishna AM, Hunke C, Weigelt S, Sewald N, Gruber G Proteins. 2009 Jun;75(4):807-19. PMID:19003877[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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