title: Sox transcription in sarcosine utilization is controlled by Sigma(54) and SoxR in Bacillus thuringiensis HD73.
abstract: Sarcosine oxidase catalyzes the oxidative demethylation of sarcosine to yield glycine, formaldehyde, and hydrogen peroxide. In this study, we analyzed the transcription and regulation of the sox locus, including the sarcosine oxidase-encoding genes in Bacillus thuringiensis (Bt). RT-PCR analysis revealed that the sox locus forms two opposing transcriptional units: soxB (soxB/E/F/G/H/I) and soxR (soxR/C/D/A). The typical -12/-24 consensus sequence was located 15 bp and 12 bp from the transcriptional start site (TSS) of soxB and soxC, respectively. Promoter-lacZ fusion assays showed that the soxB promoter is controlled by the Sigma(54) factor and is activated by the Sigma(54)-dependent transcriptional regulator SoxR. SoxR also inhibits its own expression. Expression from the PsoxCR promoter, which is responsible for the transcription of soxC, soxD, and soxA, is Sigma(54)-dependent and requires SoxR. An 11-bp inverted repeat sequence was identified as SoxR binding site upstream of the soxB TSS. Purified SoxR specifically bound a DNA fragment containing this region. Mutation or deletion of this sequence abolished the transcriptional activities of soxB and soxC. Thus, SoxR binds to the same sequence to activate the transcription of soxB and soxC. Sarcosine utilization was abolished in soxB and soxR mutants, suggesting that the sox locus is essential for sarcosine utilization.
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Peng
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Chunxia
authors.initials: C
authors.lastname: Liu
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.|College of Life Sciences, Northeast Agriculture University, Harbin, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Wang
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Min
authors.initials: M
authors.lastname: Yang
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Jianbo
authors.initials: J
authors.lastname: Wu
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Fuping
authors.initials: F
authors.lastname: Song
mesh_terms: D001413:Bacillus thuringiensis / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001665:Binding Sites; D016384:Consensus Sequence / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D009154:Mutation; D011401:Promoter Regions, Genetic; D055748:SOXB1 Transcription Factors / Q000235:genetics* / Q000378:metabolism; D012521:Sarcosine / Q000235:genetics / Q000378:metabolism*; D012808:Sigma Factor / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D055748:SOXB1 Transcription Factors; D012808:Sigma Factor; D014157:Transcription Factors; C070724:SoxR protein, Bacteria; D012521:Sarcosine