Glutamic acid 160 is the acid-base catalyst of beta-xylosidase from Bacillus stearothermophilus T-6: a family 39 glycoside hydrolase |
| |
Authors: | Bravman T Mechaly A Shulami S Belakhov V Baasov T Shoham G Shoham Y |
| |
Institution: | Department of Food Engineering and Biotechnology, Technion Isreal Institute of Technology, Haifa 32000, Israel. |
| |
Abstract: | A beta-xylosidase from Bacillus stearothermophilus T-6 was cloned, overexpressed in Escherichia coli and purified to homogeneity. Based on sequence alignment, the enzyme belongs to family 39 glycoside hydrolases, which itself forms part of the wider GH-A clan. The conserved Glu160 was proposed as the acid-base catalyst. An E160A mutant was constructed and subjected to steady state and pre-steady state kinetic analysis together with azide rescue and pH activity profiles. The observed results support the assignment of Glu160 as the acid-base catalytic residue. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|