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σ 28 RNA polymerase regulates hctB , a late developmental gene in Chlamydia
Author(s) -
Hiu Yin Yu Hilda,
Tan Ming
Publication year - 2003
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1046/j.1365-2958.2003.03708.x
Subject(s) - sigma factor , biology , rna polymerase , rna polymerase ii , polymerase , transcription (linguistics) , rna polymerase i , microbiology and biotechnology , transcription factor ii d , rna polymerase ii holoenzyme , rna dependent rna polymerase , rna polymerase iii , gene expression , rna , gene , genetics , promoter , linguistics , philosophy
Summary Chlamydia is predicted to encode two alternative sigma factors that could provide a mechanism for the regulation of gene expression via alternative forms of RNA polymerase. We have demonstrated that σ 28 , one of these alternative sigma factors, is transcriptionally active. Chlamydial σ 28 RNA polymerase was reconstituted from recombinant σ 28 protein and core enzyme that was biochemically isolated from chlamydiae. In an in vitro transcription assay, σ 28 RNA polymerase transcribed the hctB promoter in a σ 28 ‐dependent manner. Transcription by σ 28 RNA polymerase was salt tolerant compared with transcription by σ 66 RNA polymerase, the major form of chlamydial RNA polymerase. As hctB encodes a histone‐like protein that is only expressed late in the developmental cycle, our results suggest that σ 28 RNA polymerase has a role in the regulation of late gene expression in Chlamydia .