The Crystal Structure of UehA in Complex with Ectoine—A Comparison with Other TRAP-T Binding Proteins
| Autor: | Marco Pittelkow, Lutz Schmitt, Justin Lecher, Sander H. J. Smits, Tobias Bönig, Erhard Bremer, Silke Zobel, Jan Bursy |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Models
Molecular Stereochemistry ATP-binding cassette transporter Plasma protein binding Ectoine Crystallography X-Ray Ligands Protein Structure Secondary Substrate Specificity chemistry.chemical_compound Protein structure Bacterial Proteins Structural Biology Rhodobacteraceae Binding site Molecular Biology Silicibacter pomeroyi Binding Sites biology Amino Acids Diamino Biological Transport biology.organism_classification Ligand (biochemistry) Kinetics Biochemistry chemistry Periplasmic Binding Proteins Halomonas Genome Bacterial Protein Binding |
| Zdroj: | Journal of Molecular Biology. 389:58-73 |
| ISSN: | 0022-2836 |
| DOI: | 10.1016/j.jmb.2009.03.077 |
| Popis: | Substrate-binding proteins or extracellular solute receptors (ESRs) are components of both ABC (ATP binding cassette) and TRAP-T (tripartite ATP-independent periplasmic transporter). The TRAP-T system UehABC from Silicibacter pomeroyi DSS-3 imports the compatible solutes ectoine and 5-hydroxyectoine as nutrients. UehA, the ESR of the UehABC operon, binds both ectoine and 5-hydroxyectoine with high affinity (K(d) values of 1.4+/-0.1 and 1.1+/-0.1 microM, respectively) and delivers them to the TRAP-T complex. The crystal structure of UehA in complex with ectoine was determined at 2.9-A resolution and revealed an overall fold common for all ESR proteins from TRAP systems determined so far. A comparison of the recently described structure of TeaA from Halomonas elongata and an ectoine-binding protein (EhuB) from an ABC transporter revealed a conserved ligand binding mode that involves both directed and cation-pi interactions. Furthermore, a comparison with other known TRAP-T ESRs revealed a helix that might act as a selectivity filter imposing restraints on the ESRs that fine-tune ligand recognition and binding and finally might determine the selection of the cognate substrate. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect