Principal Sigma Subunit of the Caulobacter Crescentus RNA Polymerase
Document Type
Article
Abstract
We have identified the gene encoding the Caulobacter crescentus principal sigma subunit, RpoD. The rpoD gene codes for a polypeptide of 653 amino acids with a predicted molecular mass of 72,623 Da (σ73). The C. crescentus sigma subunit has extensive amino acid sequence homology with the principal sigma factors of a number of divergent procaryotes. In particular, the segments designated region 2 that are involved in core polymerase binding and promoter recognition were identical among these bacteria despite the fact that the -10 region recognized by the C. crescentus σ73 differs significantly from that of the other bacteria. Thus, it appears that additional sigma factor regions must be involved in -10 region recognition. This conclusion was strengthened by a heterologous complementation assay in which C. crescentus σ73 was capable of complementing the Escherichia coli rpoD285 temperature-sensitive mutant. Furthermore, C. crescentus σ73 conferred new specificity on the E. coli RNA polymerase, allowing the expression of C. crescentus promoters in E. coli. Thus, the C. crescentus σ73 appears to have a broader specificity than dues the σ70 of the enteric bacteria.
Digital Object Identifier (DOI)
Publication Info
Published in Journal of Bacteriology, Volume 176, Issue 23, 1995, pages 6854-6860.
Rights
© 1995, American Society for Microbiology
APA Citation
Malakooti, J., & Ely, B. (1995). Principal sigma subunit of the Caulobacter crescentus RNA polymerase. Journal of Bacteriology, 177(23), 6854–6860.https://doi.org/10.1128/jb.177.23.6854-6860.1995