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Indexed by:期刊论文

Date of Publication:2017-10-01

Journal:FEBS LETTERS

Included Journals:Scopus、SCIE、PubMed

Volume:591

Issue:20

Page Number:3402-3413

ISSN No.:1873-3468

Key Words:meso-2; 3-butanediol dehydrogenase; rational design; short-chain dehydrogenase/reductase

Abstract:Meso-2,3-butanediol dehydrogenase (meso-2,3-BDH) catalyzes NAD(+)-dependent conversion of meso-2,3-butanediol to acetoin, a crucial external energy storage molecule in fermentive bacteria. In this study, the active tunnel of meso-2,3-BDH was identified. The two short helixes positioned away from the 4-helix possibly expose the hydrophobic ligand-binding cavity, gating the exit of product and cofactor from the activity pocket. Further MM/GBSA-binding free energy analysis shows that Phe212 and Asn146 function as the key product-release sites. Site-directed mutagenesis experiments targeted to the sites show that the k(cat) of Phe212Tyr is enhanced up to (4-8)-fold. The original activity of Asn146Gln is retained, but the activity of Asn146Ala mutation is lost. These results could provide helpful guidance on rational design of short-chain dehydrogenases/reductases.