Format

Send to:

Choose Destination
See comment in PubMed Commons below
Infect Immun. 1991 Jan;59(1):137-42.

An upstream regulatory sequence stimulates expression of the perfringolysin O gene of Clostridium perfringens.

Author information

  • 1Department of Microbiology, Kagawa Medical School, Japan.

Abstract

The structural gene for perfringolysin O (pfoA), a thiol-activated hemolysin of Clostridium perfringens, was cloned into Escherichia coli JM109 on a 4.6-kilobase (kb) EcoRI-NdeI fragment which contained the 1.7-kb pfoA gene and an upstream 2.9-kb region. An E. coli strain transformed by this plasmid produced 20-fold more perfringolysin O than a strain containing only the 1.7-kb pfoA gene. The stimulatory effect of the upstream region on in vivo expression of the pfoA gene was further analyzed by using a set of deletion mutants. Stimulation was still observed with a 3.9-kb fragment, but stimulation was not observed with fragments that were 3.6 kb or less long, indicating that the upstream region between 3.9 and 1.7 kb was involved in activation of pfoA gene expression. Nucleotide sequencing showed that this region contained one open reading frame (pfoR) coding for 343 amino acids. The deduced amino acid sequence of pfoR possesses several motifs that are characteristic of DNA-binding proteins. When a region coding for a helix-turn-helix, one of the most important motifs of DNA-binding proteins, was deleted within pfoR, stimulation was completely abolished. These results indicate that pfoR positively controls expression of the pfoA gene.

PMID:
1987025
[PubMed - indexed for MEDLINE]
PMCID:
PMC257717
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk