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Site-directed mutagenesis of possible catalytic residues of cellobiose 2-epimerase from Ruminococcus albus
| Title: | Site-directed mutagenesis of possible catalytic residues of cellobiose 2-epimerase from Ruminococcus albus |
| Authors: | Ito, Shigeaki Browse this author | | Hamada, Shigeki Browse this author | | Ito, Hiroyuki Browse this author | | Matsui, Hirokazu Browse this author →KAKEN DB | | Ozawa, Tadahiro Browse this author | | Taguchi, Hidenori Browse this author | | Ito, Susumu Browse this author |
| Keywords: | Cellobiose 2-epimerase | | Ruminococcus albus | | Homology modeling | | Site-directed mutagenesis | | Epilactose | | Prebiotics |
| Issue Date: | Jul-2009 |
| Publisher: | Springer Netherlands |
| Journal Title: | Biotechnology Letters |
| Volume: | 31 |
| Issue: | 7 |
| Start Page: | 1065 |
| End Page: | 1071 |
| Publisher DOI: | 10.1007/s10529-009-9979-3 |
| PMID: | 19330485 |
| Abstract: | Cellobiose 2-epimerase (EC 5.1.3.11) from Ruminococcus albus (RaCE) catalyzes the reversible epimerization of cellobiose and lactose to 4-O-β-D-glucopyranosyl-D-mannose and 4-O-β-D-galactopyranosyl-D-mannose (epilactose). Based on the structure-based amino acid sequence alignment with N-acetyl-D-glucosamine 2-epimerases (EC 5.1.3.8) from porcine kidney and Anabaena sp. CH1 and on the computer-aided model building of the tertiary structure of RaCE, we performed site-directed mutagenesis of possible catalytic residues in the enzyme, and the mutants were expressed in Escherichia coli cells. It was found that R52, H243, E246, W249, M251, W304, E308, H374, and M378 were absolutely required for the activity of RaCE. F114 and W303 (and possibly R377) also contributed to catalysis. These possible catalytic protruded into or near the active-site cleft surrounded by the inner α-helices in the predicted (α/α)6 core barrel structure of RaCE. |
| Rights: | The original publication is available at
springerlink.com |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/38754 |
| Appears in Collections: | 創成研究機構 (Creative Research Institution) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 伊藤 進
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