title: Identification and characterization of genes involved in the downstream degradation pathway of gamma-hexachlorocyclohexane in Sphingomonas paucimobilis UT26.
abstract: Sphingomonas paucimobilis UT26 utilizes gamma-hexachlorocyclohexane (gamma-HCH) as a sole source of carbon and energy. In our previous study, we cloned and characterized genes that are involved in the conversion of gamma-HCH to maleylacetate (MA) via chlorohydroquinone (CHQ) in UT26. In this study, we identified and characterized an MA reductase gene, designated linF, that is essential for the utilization of gamma-HCH in UT26. A gene named linEb, whose deduced product showed significant identity to LinE (53%), was located close to linF. LinE is a novel type of ring cleavage dioxygenase that catalyzes the conversion of CHQ to MA. LinEb expressed in Escherichia coli transformed CHQ and 2,6-dichlorohydroquinone to MA and 2-chloromaleylacetate, respectively. Our previous and present results indicate that UT26 (i) has two gene clusters for degradation of chlorinated aromatic compounds via hydroquinone-type intermediates and (ii) uses at least parts of both clusters for gamma-HCH utilization.
authors.affiliation: Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai, 980-8577, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Endo
authors.forename: Mayuko
authors.initials: M
authors.lastname: Kamakura
authors.forename: Keisuke
authors.initials: K
authors.lastname: Miyauchi
authors.forename: Masao
authors.initials: M
authors.lastname: Fukuda
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Ohtsubo
authors.forename: Masataka
authors.initials: M
authors.lastname: Tsuda
authors.forename: Yuji
authors.initials: Y
authors.lastname: Nagata
mesh_terms: D001483:Base Sequence; D001673:Biodegradation, Environmental; D017931:DNA Primers; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D004926:Escherichia coli / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D001556:Hexachlorocyclohexane / Q000378:metabolism*; D008954:Models, Biological; D016366:Open Reading Frames; D010957:Plasmids / Q000235:genetics; D016133:Polymerase Chain Reaction; D015183:Restriction Mapping; D020578:Sphingomonas / Q000235:genetics* / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D004269:DNA, Bacterial; D001556:Hexachlorocyclohexane