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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2011-4-8
pubmed:databankReference
pubmed:abstractText
The tfoX (also called sxy) gene product is the central regulator of DNA uptake in the naturally competent bacteria Haemophilus influenzae and Vibrio cholerae. However, the mechanisms regulating tfoX gene expression in both organisms are poorly understood. Our previous studies revealed that in V. cholerae, chitin disaccharide (GlcNAc)? is needed to activate the transcription and translation of V. cholerae tfoX (tfoX(VC)) to induce natural competence. In this study, we screened a multicopy library of V. cholerae DNA fragments necessary for translational regulation of tfoX(VC). A clone carrying the VC2078-VC2079 intergenic region, designated tfoR, increased the expression of a tfoX(VC)::lacZ translational fusion constructed in Escherichia coli. Using a tfoX(VC)::lacZ reporter system in V. cholerae, we confirmed that tfoR positively regulated tfoX(VC) expression at the translational level. Deletion of tfoR abolished competence for exogenous DNA even when (GlcNAc)? was provided. The introduction of a plasmid clone carrying the tfoR(+) gene into the tfoR deletion mutant complemented the competence deficiency. We also found that the tfoR gene encodes a 102-nucleotide small RNA (sRNA), which was transcriptionally activated in the presence of (GlcNAc)?. Finally, we showed that this sRNA activated translation from tfoX(VC) mRNA in a highly purified in vitro translation system. Taking these results together, we propose that in the presence of (GlcNAc)?, TfoR sRNA is expressed to activate the translation of tfoX(VC), which leads to the induction of natural competence.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1098-5530
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
193
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1953-65
pubmed:dateRevised
2011-10-3
pubmed:meshHeading
pubmed-meshheading:21317321-Artificial Gene Fusion, pubmed-meshheading:21317321-Base Sequence, pubmed-meshheading:21317321-Chitin, pubmed-meshheading:21317321-DNA, Bacterial, pubmed-meshheading:21317321-Escherichia coli, pubmed-meshheading:21317321-Gene Deletion, pubmed-meshheading:21317321-Gene Expression Profiling, pubmed-meshheading:21317321-Gene Expression Regulation, Bacterial, pubmed-meshheading:21317321-Gene Library, pubmed-meshheading:21317321-Genes, Reporter, pubmed-meshheading:21317321-Genetic Complementation Test, pubmed-meshheading:21317321-Genetic Testing, pubmed-meshheading:21317321-Molecular Sequence Data, pubmed-meshheading:21317321-Protein Biosynthesis, pubmed-meshheading:21317321-RNA, Small Interfering, pubmed-meshheading:21317321-Sequence Analysis, DNA, pubmed-meshheading:21317321-Transformation, Bacterial, pubmed-meshheading:21317321-Vibrio cholerae, pubmed-meshheading:21317321-beta-Galactosidase
pubmed:year
2011
pubmed:articleTitle
Identification of a chitin-induced small RNA that regulates translation of the tfoX gene, encoding a positive regulator of natural competence in Vibrio cholerae.
pubmed:affiliation
Department of Bacteriology I, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan. yshouji@nih.go.jp
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't