1II9

CRYSTAL STRUCTURE OF THE ESCHERICHIA COLI ARSENITE-TRANSLOCATING ATPASE IN COMPLEX WITH AMP-PNP

Summary for 1II9

• Entry DOI: 10.2210/pdb1ii9/pdb
• Related: 1F48 1IHU 1II0
• Descriptor: ARSENICAL PUMP-DRIVING ATPASE, MAGNESIUM ION, CADMIUM ION, ... (8 entities in total)
• Functional Keywords: arsa atpase, amp-pnp, atp binding site, hydrolase
• Biological source: Escherichia coli
• Total number of polymer chains: 2
• Total formula weight: 132657.45

Authors

Zhou, T.,Radaev, S.,Gatti, D.L.,Rosen, B.P. (deposition date: 2001-04-21, release date: 2001-09-12, Last modification date: 2024-02-07)

Primary citation

Zhou, T.,Radaev, S.,Rosen, B.P.,Gatti, D.L.
Conformational changes in four regions of the Escherichia coli ArsA ATPase link ATP hydrolysis to ion translocation.
J.Biol.Chem., 276:30414-30422, 2001

PubMed Abstract: Structures of ArsA with ATP, AMP-PNP, or ADP.AlF(3) bound at the A2 nucleotide binding site were determined. Binding of different nucleotides modifies the coordination sphere of Mg(2+). In particular, the changes elicited by ADP.AlF(3) provide insights into the mechanism of ATP hydrolysis. In-line attack by water onto the gamma-phosphate of ATP would be followed first by formation of a trigonal intermediate and then by breaking of the scissile bond between the beta- and gamma-phosphates. Motions of amino acid side chains at the A2 nucleotide binding site during ATP binding and hydrolysis propagate at a distance, producing conformational changes in four different regions of the protein corresponding to helices H4-H5, helices H9-H10, helices H13-H15, and to the S1-H2-S2 region. These elements are extensions of, respectively, the Switch I and Switch II regions, the A-loop (a small loop near the nucleotide adenine moiety), and the P-loop. Based on the observed conformational changes, it is proposed that ArsA functions as a reciprocating engine that hydrolyzes 2 mol of ATP per each cycle of ion translocation across the membrane.

PubMed: 11395509
DOI: 10.1074/jbc.M103671200

Experimental method

X-RAY DIFFRACTION (2.6 Å)