Open AccessDistribution of γ‐hexachlorocyclohexane‐degrading genes on three replicons in Sphingobium japonicum UT26
Author(s) -
Nagata Yuji,
Kamakura Mayuko,
Endo Ryo,
Miyazaki Ryo,
Ohtsubo Yoshiyuki,
Tsuda Masataka
Publication year - 2006
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2005.00096.x
Subject(s) - biology , replicon , plasmid , gene , genetics , operon , microbiology and biotechnology , escherichia coli
Sphingobium japonicum (formerly Sphingomonas paucimobilis ) UT26 utilizes the important insecticide γ‐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 γ‐hexachlorocyclohexane to β‐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 γ‐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 γ‐hexachlorocyclohexane degradation are dispersed on the three large replicons of UT26.