Send to:

Choose Destination
See comment in PubMed Commons below
Microbiology. 2004 Sep;150(Pt 9):2985-92.

A differential effect of sigmaS on the expression of the PHO regulon genes of Escherichia coli.

Author information

  • 1Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Professor Lineu Prestes, 1374, São Paulo-SP CEP:05508-900, Brazil.


The RNA polymerase core associated with sigma(S) transcribes many genes related to stress or to the stationary phase. When cells enter a phase of phosphate starvation, the transcription of several genes and operons, collectively known as the PHO regulon, is strongly induced. The promoters of the PHO genes hitherto analysed are recognized by sigma(D)-associated RNA polymerase. A mutation in the gene that encodes sigma(S), rpoS, significantly increases the level of alkaline phosphatase activity and the overproduction of sigma(S) inhibits it. Other PHO genes such as phoE and ugpB are likewise affected by sigma(S). In contrast, pstS, which encodes a periplasmic phosphate-binding protein and is a negative regulator of PHO, is stimulated by sigma(S). The effect of sigma(S) on the PHO genes is at the transcriptional level. It is shown that a cytosine residue at position -13 is important for the positive effect of sigma(S) on pst. The interpretation of these observations is based on the competition between sigma(S) and sigma(D) for the binding to the core RNA polymerase.

[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Ingenta plc
    Loading ...
    Write to the Help Desk