Release Time:2019-03-11  Hits:

Indexed by: Journal Article

Date of Publication: 2017-10-01

Journal: FEBS LETTERS

Included Journals: PubMed、SCIE、Scopus

Volume: 591

Issue: 20

Page Number: 3402-3413

ISSN: 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.