Premium
The RpoN‐box motif of the RNA polymerase sigma factor σ N plays a role in promoter recognition
Author(s) -
Taylor Mark,
Butler Robin,
Chambers Sheila,
Casimiro Matthew,
Badii Farah,
Merrick Mike
Publication year - 1996
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.1365-2958.1996.01547.x
Subject(s) - rpon , biology , sigma factor , rna polymerase , polymerase , gene , sequence motif , genetics , specificity factor , promoter , microbiology and biotechnology , rna , gene expression
The RNA polymerase sigma factor σ N (σ 54 ) is characterized by the presence, near the C‐terminal end of the protein, of a highly conserved sequence of 10 amino acids (ARRTVAKYRE) that has been termed the RpoN box. In order to examine the function of this motif, which is predicted to adopt an α‐helical stucture, we have isolated a number of mutations that alter residues within the box and examined the properties of the σ N derivatives encoded by them. Certain mutations that alter charged and potentially exposed residues within the motif result in transcriptionally inactive proteins with impaired promoter recognition but no impairment in core RNA polymerase binding. We therefore suggest that the RpoN box could play a direct or indirect role in recognition of the −24, −12 promoter consensus that is characteristic of σ N ‐dependent genes.