Publication
Article Metrics
Citations
Online attention
Structural and functional investigation of the periplasmic arsenate-binding protein ArrX from Chrysiogenes arsenatis
DOI:
10.1021/acs.biochem.0c00555
Authors:
Nilakhi
Poddar
(The University of Melbourne)
,
Consuelo
Badilla
(University College London)
,
Shadi
Maghool
(The University of Melbourne)
,
Thomas H.
Osborne
(University College London)
,
Joanne M.
Santini
(University College London)
,
Megan J.
Maher
(The University of Melbourn; La Trobe University)
Co-authored by industrial partner:
No
Type:
Journal Paper
Journal:
Biochemistry
State:
Published (Approved)
Published:
February 2021
Abstract: The anaerobic bacterium Chrysiogenes arsenatis respires using the oxyanion arsenate (AsO43–) as the terminal electron acceptor, where it is reduced to arsenite (AsO33–) while concomitantly oxidizing various organic (e.g., acetate) electron donors. This respiratory activity is catalyzed in the periplasm of the bacterium by the enzyme arsenate reductase (Arr), with expression of the enzyme controlled by a sensor histidine kinase (ArrS) and a periplasmic-binding protein (PBP), ArrX. Here, we report for the first time, the molecular structure of ArrX in the absence and presence of bound ligand arsenate. Comparison of the ligand-bound structure of ArrX with other PBPs shows a high level of conservation of critical residues for ligand binding by these proteins; however, this suite of PBPs shows different structural alterations upon ligand binding. For ArrX and its homologue AioX (from Rhizobium sp. str. NT-26), which specifically binds arsenite, the structures of the substrate-binding sites in the vicinity of a conserved and critical cysteine residue contribute to the discrimination of binding for these chemically similar ligands.
Journal Keywords: Chemical structure; Anions; Peptides and proteins; Crystal structure; Ions
Subject Areas:
Biology and Bio-materials,
Chemistry
Instruments:
I04-Macromolecular Crystallography
Other Facilities: MX2 beamline at Australian Synchrotron
Discipline Tags:
Technical Tags: