3HCQ

Structural analysis of the choline binding protein ChoX in a semi-closed and ligand-free conformation

Summary for 3HCQ

• Entry DOI: 10.2210/pdb3hcq/pdb
• Related: 2REG 2RIN
• Descriptor: Putative choline ABC transporter, periplasmic solute-binding component (1 entity in total)
• Functional Keywords: transport, abc transporter, binding protein, semi-closed, choline-binding protein
• Biological source: Sinorhizobium meliloti (Sinorhizobium meliloti)
• Total number of polymer chains: 2
• Total formula weight: 64604.03

Authors

Oswald, C.,Smits, S.H.J.,Hoeing, M.,Bremer, E.,Schmitt, L. (deposition date: 2009-05-06, release date: 2009-10-13, Last modification date: 2023-09-06)

Primary citation

Oswald, C.,Smits, S.H.,Hoing, M.,Bremer, E.,Schmitt, L.
Structural analysis of the choline-binding protein ChoX in a semi-closed and ligand-free conformation.
Biol.Chem., 390:1163-1170, 2009

PubMed Abstract: The periplasmic ligand-binding protein ChoX is part of the ABC transport system ChoVWX that imports choline as a nutrient into the soil bacterium Sinorhizobium meliloti. We have recently reported the crystal structures of ChoX in complex with its ligands choline and acetylcholine and the structure of a fully closed but substrate-free state of ChoX. This latter structure revealed an architecture of the ligand-binding site that is superimposable to the closed, ligand-bound form of ChoX. We report here the crystal structure of ChoX in an unusual, ligand-free conformation that represents a semi-closed form of ChoX. The analysis revealed a subdomain movement in the N-lobe of ChoX. Comparison with the two well-characterized substrate binding proteins, MBP and HisJ, suggests the presence of a similar subdomain in these proteins.

PubMed: 19642870
DOI: 10.1515/BC.2009.113

Experimental method

X-RAY DIFFRACTION (2.89 Å)