Distribution of gamma-hexachlorocyclohexane-degrading genes on three replicons in Sphingobium japonicum UT26.
Sphingobium japonicum (formerly Sphingomonas paucimobilis) UT26 utilizes the important insecticide gamma-hexachlorocyclohexane as a sole source of carbon and energy. In previous studies, we isolated and characterized six structural genes (linA to linF) and one regulatory gene (linR) of UT26 for the degradation of gamma-hexachlorocyclohexane to beta-ketoadipate. Our analysis in this study indicated that the UT26 genome consists of three large circular replicons of 3.6 Mb, 670 kb, and 185 kb. The 3.6 Mb and the 670 kb replicons had one and two copies, respectively, of the 16S ribosomal RNA gene, and these replicons were designated as chromosomes (Chr) I and II, respectively. Chr I was indicated to be a main chromosome carrying the dnaA gene. The first three lin genes, linA to linC, for conversion of gamma-hexachlorocyclohexane to 2,5-dichlorohydroquinone, were dispersed on Chr I. The 185 kb plasmid, pCHQ1, carried the linRED operon for the conversion of 2,5-dichlorohydroquinone to maleylacetate and was conjugatively transferred to another sphingomonad strain. The linF gene encoding maleylacetate reductase was located on Chr II. These results indicated that the genes for the complete gamma-hexachlorocyclohexane degradation are dispersed on the three large replicons of UT26.
Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Japan. aynaga@ige.tohoku.ac.jp
Yuji
Y
Nagata
Mayuko
M
Kamakura
Ryo
R
Endo
Ryo
R
Miyazaki
Yoshiyuki
Y
Ohtsubo
Masataka
M
Tsuda
D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D002874:Chromosome Mapping / Q000379:methods; D003227:Conjugation, Genetic / Q000235:genetics; D004262:DNA Restriction Enzymes; D004268:DNA-Binding Proteins / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods; D023061:Gene Order / Q000235:genetics*; D016680:Genome, Bacterial / Q000235:genetics*; D001556:Hexachlorocyclohexane / Q000378:metabolism*; D008969:Molecular Sequence Data; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012093:Replicon / Q000235:genetics*; D042301:Sphingomonadaceae / Q000235:genetics*
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C066312:DnaA protein, Bacteria; D012336:RNA, Ribosomal, 16S; D001556:Hexachlorocyclohexane; D004262:DNA Restriction Enzymes