Dataset Information

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

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.

SUBMITTER: Shimizu T

PROVIDER: S-EPMC257717 | biostudies-other | 1991 Jan

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

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

Shimizu T T Okabe A A Minami J J Hayashi H H

Infection and immunity 19910101 1

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 ...[more]

PMID: 1987025

Similar Datasets

Project description:BACKGROUND: Cysteine has a crucial role in cellular physiology and its synthesis is tightly controlled due to its reactivity. However, little is known about the sulfur metabolism and its regulation in clostridia compared with other firmicutes. In Clostridium perfringens, the two-component system, VirR/VirS, controls the expression of the ubiG operon involved in methionine to cysteine conversion in addition to the expression of several toxin genes. The existence of links between the C. perfringens virulence regulon and sulfur metabolism prompted us to analyze this metabolism in more detail. RESULTS: We first performed a tentative reconstruction of sulfur metabolism in C. perfringens and correlated these data with the growth of strain 13 in the presence of various sulfur sources. Surprisingly, C. perfringens can convert cysteine to methionine by an atypical still uncharacterized pathway. We further compared the expression profiles of strain 13 after growth in the presence of cystine or homocysteine that corresponds to conditions of cysteine depletion. Among the 177 genes differentially expressed, we found genes involved in sulfur metabolism and controlled by premature termination of transcription via a cysteine specific T-box system (cysK-cysE, cysP1 and cysP2) or an S-box riboswitch (metK and metT). We also showed that the ubiG operon was submitted to a triple regulation by cysteine availability via a T-box system, by the VirR/VirS system via the VR-RNA and by the VirX regulatory RNA.In addition, we found that expression of pfoA (theta-toxin), nagL (one of the five genes encoding hyaluronidases) and genes involved in the maintenance of cell redox status was differentially expressed in response to cysteine availability. Finally, we showed that the expression of genes involved in [Fe-S] clusters biogenesis and of the ldh gene encoding the lactate dehydrogenase was induced during cysteine limitation. CONCLUSION: Several key functions for the cellular physiology of this anaerobic bacterium were controlled in response to cysteine availability. While most of the genes involved in sulfur metabolism are regulated by premature termination of transcription, other still uncharacterized mechanisms of regulation participated in the induction of gene expression during cysteine starvation.

Dataset Information

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

Publications

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

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets