English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Halohydrin dehalogenase fromAgrobacterium radiobacter AD1 (HheC) is a valuable tool in the preparation ofR enantiomers of epoxides and β-substituted alcohols. In contrast, the halohydrin dehalogenase fromArthrobacter sp. AD2 (HheA) shows a lowS enantioselectivity toward most aromatic substrates. Here, three amino acids (V136, L141, and N178) located in the two neighboring active-site loops of HheA were proposed to be the key residues for controlling enantioselectivity. They were subjected to saturation mutagenesis aimed at evolving anS -selective enzyme. This led to the selection of two outstanding mutants (the V136Y/L141G and N178A mutants). The double mutant displayed an inverted enantioselectivity (fromS enantioselectivity [ES ] = 1.7 toR enantioselectivity [ER ] = 13) toward 2-chloro-1-phenylethanol without compromising enzyme activity. Strikingly, the N178A mutant showed a large enantioselectivity improvement (ES &gt; 200) and a 5- to 6-fold-enhanced specific activity toward (S )-2-chloro-1-phenylethanol. Further analysis revealed that those mutations produced some interference for the binding of nonfavored enantiomers which could account for the observed enantioselectivities. Our work demonstrated that those three active-site residues are indeed crucial in modulating the enantioselectivity of HheA and that a semirational design strategy has great potential for rapid creation of novel industrial biocatalysts.

applied and environmental microbiology

Key Residues for Controlling Enantioselectivity of Halohydrin Dehalogenase from Arthrobacter sp. Strain AD2, Revealed by Structure-Guided Directed Evolution