Synthesis of cholera toxin is positively regulated at the transcriptional level by toxR.
AUTOR(ES)
Miller, V L
RESUMO
We have cloned a positive regulatory gene ( toxR ) from Vibrio cholerae that controls cholera toxin transcription. This was done by first constructing a genetic fusion consisting of the lacZ gene fused to the promoter of the cholera toxin operon ctxAB . This operon fusion was used to screen a V. cholerae genomic library for genes that could activate the ctx promoter in Escherichia coli. This method allowed the identification of a gene, toxR , that increases ctx expression by more than 100-fold. Complementation analysis indicated that certain hypotoxinogenic mutants of V. cholerae 569B probably have mutations in the toxR gene. Southern blot analysis suggests that all V. cholerae, including nontoxinogenic strains, have the toxR gene. Moreover, nontoxinogenic strains not only lack the structural genes for cholera toxin but also sequences associated with the larger 7-kilobase ctx genetic element.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=345530Documentos Relacionados
- Genetic analysis of the cholera toxin-positive regulatory gene toxR.
- Mutations in toxR and toxS That Separate Transcriptional Activation from DNA Binding at the Cholera Toxin Gene Promoter
- Expression of the Vibrio cholerae gene encoding aldehyde dehydrogenase is under control of ToxR, the cholera toxin transcriptional activator.
- The pepR Gene of Lactobacillus sakei Is Positively Regulated by Anaerobiosis at the Transcriptional Level
- Identification of Vibrio parahaemolyticus Strains at the Species Level by PCR Targeted to the toxR Gene