title: Kinetic and sequence-structure-function analysis of LinB enzyme variants with β- and δ-hexachlorocyclohexane.
abstract: Organochlorine insecticide hexachlorocyclohexane (HCH) has recently been classified as a 'Persistent Organic pollutant' by the Stockholm Convention. The LinB haloalkane dehalogenase is a key upstream enzyme in the recently evolved Lin pathway for the catabolism of HCH in bacteria. Here we report a sequence-structure-function analysis of ten naturally occurring and thirteen synthetic mutants of LinB. One of the synthetic mutants was found to have ∼80 fold more activity for β- and δ-hexachlorocyclohexane. Based on detailed biophysical calculations, molecular dynamics and ensemble docking calculations, we propose that the latter variant is more active because of alterations to the shape of its active site and increased conformational plasticity.
authors: CSIRO Ecosystem Sciences, Acton, ACT, Australia.
authors: Rinku
authors: R
authors: Pandey
authors: CSIRO Center for Materials Science and Engineering, Parkville VIC, Australia; Division of Engineering and Physics, Wilkes University, Wilkes-Barre, Pennsylvania, United States of America.
authors: Del
authors: D
authors: Lucent
authors: CSIRO Ecosystem Sciences, Acton, ACT, Australia; Department of Zoology, University of Delhi, Delhi, India.
authors: Kirti
authors: K
authors: Kumari
authors: CSIRO Ecosystem Sciences, Acton, ACT, Australia; Department of Zoology, University of Delhi, Delhi, India.
authors: Pooja
authors: P
authors: Sharma
authors: Department of Zoology, University of Delhi, Delhi, India.
authors: Rup
authors: R
authors: Lal
authors: CSIRO Ecosystem Sciences, Acton, ACT, Australia.
authors: John G
authors: JG
authors: Oakeshott
authors: CSIRO Ecosystem Sciences, Acton, ACT, Australia.
authors: Gunjan
authors: G
authors: Pandey
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000737:chemistry*; D020134:Catalytic Domain; D001556:Hexachlorocyclohexane / Q000737:chemistry*; D006867:Hydrolases / Q000737:chemistry*; D007306:Insecticides / Q000737:chemistry*; D007700:Kinetics; D056004:Molecular Dynamics Simulation; D008969:Molecular Sequence Data
chemical_list: D001426:Bacterial Proteins; D007306:Insecticides; C086916:delta-hexachlorocyclohexane; D001556:Hexachlorocyclohexane; D006867:Hydrolases; C046137:haloalkane dehalogenase; C023888:beta-hexachlorocyclohexane