5B12

Crystal structure of the B-type halohydrin hydrogen-halide-lyase mutant F71W/Q125T/D199H from Corynebacterium sp. N-1074

Summary for 5B12

• Entry DOI: 10.2210/pdb5b12/pdb
• Descriptor: Halohydrin epoxidase B, CHLORIDE ION (3 entities in total)
• Functional Keywords: lyase, enantioselectivity, halohydrin
• Biological source: Corynebacterium sp.
• Total number of polymer chains: 6
• Total formula weight: 152363.72

Authors

Watanabe, F.,Yu, F.,Ohtaki, A.,Yamanaka, Y.,Noguchi, K.,Odaka, M.,Yohda, M. (deposition date: 2015-11-17, release date: 2016-08-03, Last modification date: 2024-03-20)

Primary citation

Watanabe, F.,Yu, F.,Ohtaki, A.,Yamanaka, Y.,Noguchi, K.,Odaka, M.,Yohda, M.
Improvement of enantioselectivity of the B-type halohydrin hydrogen-halide-lyase from Corynebacterium sp. N-1074
J.Biosci.Bioeng., 122:270-275, 2016

PubMed Abstract: Halohydrin hydrogen-halide-lyase (H-Lyase) is a bacterial enzyme involved in the degradation of halohydrins. This enzyme catalyzes the intramolecular nucleophilic displacement of a halogen by a vicinal hydroxyl group in halohydrins, producing the corresponding epoxides. The H-Lyases have been classified into A, B and C subtypes based on amino acid sequence similarities. These enzymes have attracted much attention as industrial catalysts in the synthesis of chiral chemicals from prochiral halohydrins. In the present study, we constructed mutants of B-type H-Lyase from Corynebacterium sp. N-1074 (HheB) displaying higher enantioselectivity by structure-based site-directed mutagenesis and random mutagenesis. A triple mutant of HheB exhibited 98.5% enantioselectivity, the highest ever reported, toward (R)-4-chloro-3-hydroxy-butyronitrile production, with the yield reaching approximately two-fold that of the wild-type enzyme. We discuss the structural basis of the high enantioselectivity and productivity of the mutant by comparing the crystal structures of the mutant HheB and the wild-type enzyme in complex with or without the substrate analogue.

PubMed: 27215832
DOI: 10.1016/j.jbiosc.2016.02.003

Experimental method

X-RAY DIFFRACTION (1.721 Å)