Open AccessCascade of extracytoplasmic function sigma factors in Mycobacterium tuberculosis : identification of a σ J ‐dependent promoter upstream of sigI
Author(s) -
Homerova Dagmar,
Halgasova Lenka,
Kormanec Jan
Publication year - 2008
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.1574-6968.2007.01054.x
Subject(s) - sigma factor , rna polymerase , mycobacterium smegmatis , promoter , plasmid , biology , gene , microbiology and biotechnology , transcription (linguistics) , mycobacterium tuberculosis , escherichia coli , genetics , gene expression , tuberculosis , medicine , linguistics , philosophy , pathology
A previously optimized Escherichia coli two‐plasmid system was used to identify promoters recognized by RNA polymerase containing the Mycobacterium tuberculosis extracytoplasmic function (ECF) sigma factor σ J . The only positive clone revealed a promoter directing expression of the sigI gene encoding ECF sigma factor σ I . The transcriptional start point of the promoter was determined and the promoter was confirmed by an in vitro transcription assay with either E. coli or Mycobacterium smegmatis core RNA polymerase and isolated σ J .