title: A gene linB2 responsible for the conversion of beta-HCH and 2,3,4,5,6-pentachlorocyclohexanol in Sphingomonas sp. BHC-A.
abstract: Commercial formulations of hexachlorocyclohexane (HCH) consist of a mixture of four isomers: alpha, beta, gamma, and delta. All four isomers are toxic and recalcitrant pollutants. beta-HCH is more problematic due to its longer persistence in the environment. Sphingomonas sp. BHC-A was able to degrade not only alpha-, gamma-, and delta-HCH but also beta-HCH. To clone a gene responsible for the degradation of beta-HCH, a Tn5 mutation was introduced into BHC-A, and one mutant BHC-A45 defective in beta-HCH degradation was selected. Sequencing analysis showed this mutant had a Tn5 insertion at the site of one haloalkane dehalogenase gene, designated linB2. linB2 was overexpressed in Escherichia coli and the 32-kDa product LinB2 showed the conversion activity of not only beta-HCH to beta-2,3,4,5,6-pentachlorocyclohexanol (beta-PCHL) but also beta-PCHL to beta-2,3,5,6-tetrachloro-1,4-cyclohexanediol.
authors.affiliation: Department of Microbiology, Nanjing Agricultural University, 6 Tongwei Rd, Nanjing, Jiangsu Province, 210095, People's Republic of China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
authors.forename: Qing
authors.initials: Q
authors.lastname: Hong
authors.forename: Peng
authors.initials: P
authors.lastname: Han
authors.forename: Jian
authors.initials: J
authors.lastname: He
authors.forename: Shunpeng
authors.initials: S
authors.lastname: Li
mesh_terms: D003001:Cloning, Molecular; D003511:Cyclohexanols / Q000378:metabolism*; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D001556:Hexachlorocyclohexane / Q000378:metabolism*; D006867:Hydrolases / Q000235:genetics* / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D017422:Sequence Analysis, DNA; D020578:Sphingomonas / Q000201:enzymology* / Q000235:genetics
chemical_list: D003511:Cyclohexanols; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D011994:Recombinant Proteins; C064620:1,4-cyclohexanediol; D001556:Hexachlorocyclohexane; D006867:Hydrolases; C046137:haloalkane dehalogenase; C023888:beta-hexachlorocyclohexane