title: Genomic organization and genomic structural rearrangements of Sphingobium japonicum UT26, an archetypal γ-hexachlorocyclohexane-degrading bacterium.
abstract: The complete genome sequencing of a γ-hexachlorocyclohexane-degrading strain, Sphingobium japonicum UT26, revealed that the genome consists of two circular chromosomes [with sizes of 3.5 Mb (Chr1) and 682kb (Chr2)], a 191-kb large plasmid (pCHQ1), and two small plasmids with sizes of 32 and 5kb. The lin genes are dispersed on Chr1, Chr2, and pCHQ1. Comparison of the UT26 genome with those of other sphingomonad strains demonstrated that the "specific"lin genes for conversion of γ-HCH to β-ketoadipate (linA, linB, linC, linRED, and linF) are located on the DNA regions unique to the UT26 genome, suggesting the acquisition of these lin genes by horizontal transfer events. On the other hand, linGHIJ and linKLMN are located on the regions conserved in the genomes of sphingomonads, suggesting that the linGHIJ-encoded β-ketoadipate pathway and the LinKLMN-type ABC transporter system are involved in core functions of sphingomonads. Based on these results, we propose a hypothesis that UT26 was created by recruiting the specific lin genes into a strain having core functions of sphingomonads. Most of the specific lin genes in UT26 are associated with IS6100. Our analysis of spontaneous linA-, linC-, and linRED-deletion mutants of UT26 revealed the involvement of IS6100 in their deduced genome rearrangements. These facts strongly suggest that IS6100 plays important roles both in the dissemination of the specific lin genes and in the genome rearrangements.
authors.affiliation: Graduate School of Life Sciences, Tohoku University, Japan. aynaga@ige.tohoku.ac.jp
authors.forename: Yuji
authors.initials: Y
authors.lastname: Nagata
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Natsui
authors.forename: Ryo
authors.initials: R
authors.lastname: Endo
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Ohtsubo
authors.forename: Natsuko
authors.initials: N
authors.lastname: Ichikawa
authors.forename: Akiho
authors.initials: A
authors.lastname: Ankai
authors.forename: Akio
authors.initials: A
authors.lastname: Oguchi
authors.forename: Shigehiro
authors.initials: S
authors.lastname: Fukui
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Fujita
authors.forename: Masataka
authors.initials: M
authors.lastname: Tsuda
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism; D000272:Adipates / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001673:Biodegradation, Environmental; D017353:Gene Deletion; D015321:Gene Rearrangement; D022761:Gene Transfer, Horizontal; D005798:Genes, Bacterial; D016680:Genome, Bacterial; D001556:Hexachlorocyclohexane / Q000378:metabolism*; D053858:Metabolic Networks and Pathways; D008957:Models, Genetic; D010802:Phylogeny; D018741:Replication Origin; D012093:Replicon; D013045:Species Specificity; D042301:Sphingomonadaceae / Q000235:genetics* / Q000378:metabolism*
chemical_list: D018528:ATP-Binding Cassette Transporters; D000272:Adipates; D001426:Bacterial Proteins; C027316:3-oxoadipic acid; D001556:Hexachlorocyclohexane