6EU7

Structure of the arsenite-bound form of AioX from Rhizobium sp. str. NT-26

Summary for 6EU7

• Entry DOI: 10.2210/pdb6eu7/pdb
• Descriptor: Putative periplasmic phosphite-binding-like protein (Pbl) PtxB-like protein designated AioX (2 entities in total)
• Functional Keywords: periplasmic-binding protein, arsenic, arsenite-binding, rhizobium nt-26, signaling protein
• Biological source: Rhizobium sp. NT-26
• Total number of polymer chains: 6
• Total formula weight: 187519.18

Authors

Djordjevic, S.,Badilla, C.,Cole, A.,Santini, J. (deposition date: 2017-10-28, release date: 2018-10-17, Last modification date: 2024-11-13)

Primary citation

Badilla, C.,Osborne, T.H.,Cole, A.,Watson, C.,Djordjevic, S.,Santini, J.M.
A new family of periplasmic-binding proteins that sense arsenic oxyanions.
Sci Rep, 8:6282-6282, 2018

PubMed Abstract: Arsenic contamination of drinking water affects more than 140 million people worldwide. While toxic to humans, inorganic forms of arsenic (arsenite and arsenate), can be used as energy sources for microbial respiration. AioX and its orthologues (ArxX and ArrX) represent the first members of a new sub-family of periplasmic-binding proteins that serve as the first component of a signal transduction system, that's role is to positively regulate expression of arsenic metabolism enzymes. As determined by X-ray crystallography for AioX, arsenite binding only requires subtle conformational changes in protein structure, providing insights into protein-ligand interactions. The binding pocket of all orthologues is conserved but this alone is not sufficient for oxyanion selectivity, with proteins selectively binding either arsenite or arsenate. Phylogenetic evidence, clearly demonstrates that the regulatory proteins evolved together early in prokaryotic evolution and had a separate origin from the metabolic enzymes whose expression they regulate.

PubMed: 29674678
DOI: 10.1038/s41598-018-24591-w

Experimental method

X-RAY DIFFRACTION (3 Å)