Characterization of lipoprotein IRP1 from Corynebacterium diphtheriae, which is regulated by the diphtheria toxin repressor (DtxR) and iron.
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ABSTRACT:
SUBMITTER: Schmitt MP
PROVIDER: S-EPMC175775 | biostudies-other | 1997 Dec
REPOSITORIES: biostudies-other
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Characterization of lipoprotein IRP1 from Corynebacterium diphtheriae, which is regulated by the diphtheria toxin repressor (DtxR) and iron.
Schmitt M P MP Talley B G BG Holmes R K RK
Infection and immunity 19971201 12
The Corynebacterium diphtheriae irp1 gene is negatively regulated by DtxR and iron. The nucleotide sequence of irp1 revealed that it has homology with genes involved in iron acquisition. Expression of the irp1 gene showed that it encodes a lipoprotein (IRP1) with a predicted size of 38 kDa. Northern blot experiments indicated that transcription from the irp1 promoter is repressed in high-iron medium and suggested that irp1 is part of an iron-regulated operon. ...[more]
Similar Datasets
Project description:Nontoxigenic strains of Corynebacterium diphtheriae represent a potential reservoir for the emergence of toxigenic C. diphtheriae strains if they possessed functional diphtheria toxin repressor (dtxR) genes. We studied the predominant strain of nontoxigenic C. diphtheriae circulating in the United Kingdom to see if they possessed dtxR genes and ascertain whether they were functional. A total of 26 nontoxigenic C. diphtheriae strains isolated in the United Kingdom during 1995 and 4 nontoxigenic strains isolated in other countries were analyzed by PCR and direct sequencing to determine the presence and intactness of the dtxR genes. The functionality of the DtxR proteins was assayed by testing for the production of siderophore in medium containing high and low concentrations of iron. PCR amplification and sequence analysis of the dtxR genes revealed four variants of the predicted DtxR protein among the nontoxigenic strains isolated in the United Kingdom. Production of siderophore in medium containing a low concentration of iron and repression of siderophore production in medium containing a high concentration of iron demonstrated that in all the strains the dtxR genes were functional. These findings demonstrate that, if lysogenised by a bacteriophage, nontoxigenic strains circulating in the United Kingdom could produce toxin and therefore represent a potential reservoir for toxigenic C. diphtheriae.
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2018-09-07 | GSE119621 | GEO
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