2ck3

Publication Abstract from PubMed

In the structure of bovine F1-ATPase determined at 1.95-A resolution with crystals grown in the presence of ADP, 5'-adenylyl-imidodiphosphate, and azide, the azide anion interacts with the beta-phosphate of ADP and with residues in the ADP-binding catalytic subunit, betaDP. It occupies a position between the catalytically essential amino acids, beta-Lys-162 in the P loop and the "arginine finger" residue, alpha-Arg-373, similar to the site occupied by the gamma-phosphate in the ATP-binding subunit, betaTP. Its presence in the betaDP-subunit tightens the binding of the side chains to the nucleotide, enhancing its affinity and thereby stabilizing the state with bound ADP. This mechanism of inhibition appears to be common to many other ATPases, including ABC transporters, SecA, and DNA topoisomerase IIalpha. It also explains the stimulatory effect of azide on ATP-sensitive potassium channels by enhancing the binding of ADP.

How azide inhibits ATP hydrolysis by the F-ATPases.,Bowler MW, Montgomery MG, Leslie AG, Walker JE Proc Natl Acad Sci U S A. 2006 Jun 6;103(23):8646-9. Epub 2006 May 25. PMID:16728506^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.