Download MendeleyStructural analysis of the choline-binding protein ChoX in a semi-closed and ligand-free conformation.
Oswald, C., Smits, S.H., Hoing, M., Bremer, E., Schmitt, L.(2009) Biol Chem 390: 1163-1170
- PubMed: 19642870
- DOI: https://doi.org/10.1515/BC.2009.113
- Primary Citation of Related Structures:
3HCQ - 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.
Organizational Affiliation:
Institute of Biochemistry, Heinrich Heine University Düsseldorf, Universitätsstr. 1, D-40225 Düsseldorf, Germany.
