標題: | Identification of amino acid residues important for the phosphomannose isomerase activity of Ps1B in Pseudomonas aeruginosa PAO1 |
作者: | Lee, Hui-Ju Chang, Hwan-You Venkatesan, Nandinin Peng, Hwei-Ling 生物科技學院 College of Biological Science and Technology |
關鍵字: | GDP-mannose pyrophosphorylase;Pseudomonas aeruginosa;Phosphomannose isomerase;pslB;Site-directed mutagenesis |
公開日期: | 15-Oct-2008 |
摘要: | Phosphomannose isomerase (PMI) plays a pivotal role in biosynthesis of GDP-mannose, an important precursor of many polysaccharides. We demonstrate in this study that Pseudomonas aeruginosa pslB encodes a protein with GDP-mannose pyrophosphorylase/PMI dual activities. The PMI activity is Co2+-dependent and could be inhibited by GDP-mannose in a competitive manner. Furthermore, the activity could be inactivated by 2,3-butanedione suggesting the presence of a catalytic Arg residue. Site-specific mutations at R373, R472, R479, E410, H411, N433 and E458 increase the KM approximately 8-20-fold. The PMI activity of PslB was completely diminished with a R408K or R408A, reflecting the importance of this residue in catalysis. Overall, these results provide a basis for understanding the catalytic mechanism of PMI. |
URI: | http://dx.doi.org/10.1016/j.febslet.2008.09.013 http://hdl.handle.net/11536/8245 |
ISSN: | 0014-5793 |
DOI: | 10.1016/j.febslet.2008.09.013 |
期刊: | FEBS LETTERS |
Volume: | 582 |
Issue: | 23-24 |
起始頁: | 3479 |
結束頁: | 3483 |
Appears in Collections: | Articles |
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