Open AccessIn vitro transcription analysis of rpoD in Pseudomonas aeruginosa PAO1
Author(s) -
Aramaki Hironori,
Fujita Masaya
Publication year - 1999
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.1574-6968.1999.tb08811.x
Subject(s) - sigma factor , rna polymerase , transcription (linguistics) , microbiology and biotechnology , promoter , biology , pseudomonas aeruginosa , escherichia coli , gene , gene expression , genetics , bacteria , linguistics , philosophy
The rpoD gene encoding the principal sigma factor (σ 70 ) of Pseudomonas aeruginosa is transcribed from two promoters, P C and P HS . The sequence of P C is similar to the Escherichia coli σ 70 consensus promoter sequence and that of P HS is similar to the E. coli σ H consensus promoter sequence. Synthesis of rpoD mRNA from P C is constitutive under both steady‐state and heat‐shock growth conditions, while that of P HS is transiently induced upon heat‐shock. To gain a better understanding of the regulation of rpoD expression, we examined in vitro transcription of rpoD using two RNA polymerases (Eσ 70 and Eσ H , containing σ 70 and σ H , respectively) purified from P. aeruginosa . DNase I footprinting analysis showed specific bindings of Eσ 70 and Eσ H to P C and P HS promoter regions, respectively. In the in vitro runoff transcription assay, Eσ H transcribed the template from P HS both at 30°C and 42°C but not from P C . However, Eσ 70 transcribed rpoD not only from P C both at 30°C and 42°C but also from P HS at 42°C.