Structure-based annotation of a novel sugar isomerase from the pathogenic E. coli O157:H7
| Autor: | Chang-Su Park, Zongchao Jia, Laura M. van Staalduinen, Deok-Kun Oh, Melanie A. Adams-Cioaba, Soo-Jin Yeom |
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| Rok vydání: | 2010 |
| Předmět: |
Models
Molecular Sequence analysis Protein Conformation Molecular Sequence Data Mutagenesis (molecular biology technique) Isomerase Biology medicine.disease_cause Crystallography X-Ray Escherichia coli O157 Substrate Specificity Gene product Protein structure Structural Biology Cations medicine Amino Acid Sequence Isomerases Molecular Biology Escherichia coli Gene Peptide sequence Sequence Homology Amino Acid Genetic Complementation Test Temperature Hydrogen-Ion Concentration Biochemistry Mutation Dimerization |
| Zdroj: | Journal of molecular biology. 401(5) |
| ISSN: | 1089-8638 |
| Popis: | Prokaryotes can use a variety of sugars as carbon sources in order to provide a selective survival advantage. The gene z5688 found in the pathogenic Escherichia coli O157:H7 encodes a "hypothetical" protein of unknown function. Sequence analysis identified the gene product as a putative member of the cupin superfamily of proteins, but no other functional information was known. We have determined the crystal structure of the Z5688 protein at 1.6 A resolution and identified the protein as a novel E. coli sugar isomerase (EcSI) through overall fold analysis and secondary-structure matching. Extensive substrate screening revealed that EcSI is capable of acting on d-lyxose and d-mannose. The complex structure of EcSI with fructose allowed the identification of key active-site residues, and mutagenesis confirmed their importance. The structure of EcSI also suggested a novel mechanism for substrate binding and product release in a cupin sugar isomerase. Supplementation of a nonpathogenic E. coli strain with EcSI enabled cell growth on the rare pentose d-lyxose. |
| Databáze: | OpenAIRE |
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