title: Delineating Substrate Diversity of Disparate Short-Chain Dehydrogenase Reductase from Debaryomyces hansenii.
abstract: Short-chain dehydrogenase reductases (SDRs) have been utilized for catalyzing the reduction of many aromatic/aliphatic prochiral ketones to their respective alcohols. However, there is a paucity of data that elucidates their innate biological role and diverse substrate space. In this study, we executed an in-depth biochemical characterization and substrate space mapping (with 278 prochiral ketones) of an unannotated SDR (DHK) from Debaryomyces hansenii and compared it with structurally and functionally characterized SDR Synechococcus elongatus. PCC 7942 FabG to delineate its industrial significance. It was observed that DHK was significantly more efficient than FabG, reducing a diverse set of ketones albeit at higher conversion rates. Comparison of the FabG structure with a homology model of DHK and a docking of substrate to both structures revealed the presence of additional flexible loops near the substrate binding site of DHK. The comparative elasticity of the cofactor and substrate binding site of FabG and DHK was experimentally substantiated using differential scanning fluorimetry. It is postulated that the loop flexibility may account for the superior catalytic efficiency of DHK although the positioning of the catalytic triad is conserved.
authors.affiliation: Biomoneta Research Private Limited, Bangalore, India.
authors.forename: Arindam
authors.initials: A
authors.lastname: Ghatak
authors.affiliation: Centre for Cellular and Molecular Platforms (C-CAMP), National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India.
authors.forename: Nagakumar
authors.initials: N
authors.lastname: Bharatham
authors.affiliation: Bugworks Research India Private Limited, Bangalore, India.|Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, Kolkata, India.
authors.forename: Anirudh P
authors.initials: AP
authors.lastname: Shanbhag
authors.affiliation: Bugworks Research India Private Limited, Bangalore, India.
authors.forename: Santanu
authors.initials: S
authors.lastname: Datta
authors.affiliation: Biomoneta Research Private Limited, Bangalore, India.
authors.forename: Janani
authors.initials: J
authors.lastname: Venkatraman
mesh_terms: D000595:Amino Acid Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010088:Oxidoreductases / Q000737:chemistry / Q000378:metabolism*; D004718:Saccharomycetales / Q000201:enzymology*; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D010088:Oxidoreductases