The plasmid-encoded urease gene cluster of the family Enterobacteriaceae is positively regulated by UreR, a member of the AraC family of transcriptional activators

D’Orazio, Sarah E. F.; Collins, Carleen

doi:10.1128/jb.175.11.3459-3467.1993

Cited by 53 publications

(51 citation statements)

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“…Although the full sequence of the UPEC ureC gene is not available, phylogenetic analysis of UreA, UreB, and UreG shows that the urease genes of EHEC strains exhibit the highest degree of similarity to those of Klebsiella aerogenes, while the urease genes of UPEC are most similar to those of Proteus mirabilis (data not shown). Furthermore, the gene organizations of the urease operons were different from each other in EHEC and UPEC strains (5). These data suggest that an appropriate primer set can differentiate the EHEC ureC gene from the UPEC ureC gene.…”

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confidence: 80%

Association of the Urease Gene with Enterohemorrhagic Escherichia coli Strains Irrespective of Their Serogroups

et al. 2001

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Among various diarrheagenic Escherichia coli strains from clinical sources, we found that the urease gene was specifically associated with enterohemorrhagic E. coli (EHEC) strains irrespective of their serogroups. The results suggest that the urease gene can be a useful genetic marker for the detection of EHEC strains and for the diagnosis of infections caused by EHEC strains in the clinical situation.

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Association of the Urease Gene with Enterohemorrhagic Escherichia coli Strains Irrespective of Their Serogroups

et al. 2001

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“…The P. mirabilis urease gene cluster, ureDABCEFG, is induced in the presence of urea and UreR, the transcriptional regulator of the gene cluster (D'Orazio & Collins, 1993D'Orazio et al, 1996;Island & Mobley, 1995;Nicholson et al, 1993). P. mirabilis UreR, a dimer of 33?4 kDa polypeptides is an AraC-like transcriptional regulator that activates transcription from p ureD and p ureR in a urea-inducible manner (D'Orazio et al, 1996;Island & Mobley, 1995).…”

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confidence: 99%

Differential regulation of the Proteus mirabilis urease gene cluster by UreR and H-NS

Poore

Mobley

2003

Microbiology

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Proteus mirabilis, a cause of catheter-associated urinary tract infection, relies on several virulence factors to colonize the urinary tract. Among these, urease contributes to the development of urinary stones resulting from the increase in local pH due to urease-mediated hydrolysis of urea to NH 3 and CO 2 . UreR, an AraC-like transcriptional activator, activates transcription of the genes encoding the urease subunits and accessory proteins (ureDABCEFG) in the presence of urea. UreR also initiates transcription of its own gene in a urea-inducible manner by binding to the intergenic region between ureR and ureD. The intergenic region contains poly(A) tracts that appear to be the target of H-NS. It has been shown that Escherichia coli and P. mirabilis H-NS acts to repress transcription of ureR in an E. coli model system. It was hypothesized that H-NS represses urease gene expression in the absence of UreR and urea by binding to the intergenic region. To demonstrate this the P. mirabilis hns gene was cloned and the 15?6 kDa H-NS was overexpressed and purified as a myc-His tail fusion. Using a gel shift assay, purified H-NS-myc-His bound preferentially to a 609 bp DNA fragment containing the entire ureR-ureD intergenic region. H-NS and UreR were able to displace each other from the ureR-ureD intergenic region. Circular permutation analysis revealed that the intergenic region is bent. Moreover, H-NS recognizes this curvature, binds the DNA fragment and induces further bending of the DNA as shown by a circular ligation assay. The effects of H-NS, urea and temperature (25 vs 37 6C) on urease expression were shown in E. coli containing an hns knockout and P. mirabilis where expression was increased at 37 6C. Increased transcription from p ureR was seen in the E. coli hns knockout when temperature was increased from 25 to 37 6C. These findings suggest H-NS and UreR differentially regulate urease in a negative and positive manner, respectively.

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“…Comparison of the deduced amino acid sequence of the ORF with sequences in the GenBank database showed that the protein possesses a distinct primary sequence similarity to UreR and AraC (19 and 22% identity, respectively). This homology was essentially confined to the C-terminal sequence of each locus, especially in the amino acids that characterize the C-terminal DNA binding region for the AraC family of DNA binding proteins (6) (Fig. 4).…”

Section: Resultsmentioning

confidence: 99%

Regulation of ornithine utilization in Pseudomonas aeruginosa (PAO1) is mediated by a transcriptional regulator, OruR

Hebert

Houghton

1997

J Bacteriol

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We have used transpositional mutagenesis of a proline auxotroph (PAO951) to isolate an ornithine utilization (oru) mutant of Pseudomonas aeruginosa (PAO951-4) that was unable to use ornithine efficiently as the sole carbon and nitrogen source. DNA sequence analysis of the inactivated locus confirmed that the transposon had inserted into a locus whose product demonstrated significant primary sequence homology to members of the AraC family of transcriptional activators. DNA mobility shift assays affirmed this potential regulatory function and indicated that the inactivated gene encodes a transcriptional regulator, which has been designated OruR. In trying to define the ornithine utilization phenotype further, a similar inactivation was engineered in the wild-type strain, PAO1. The resulting isolate (PAO1R4) was totally unable to use ornithine as the sole carbon source. Despite the intensified phenotype, this isolate failed to demonstrate significant changes in any of the catabolic or anabolic enzymes that are known to be subject to regulation by the presence of either ornithine or arginine. It did, however, show modified levels of an enzyme, ornithine acetyltransferase (OAcT), that was previously thought to have merely an anaplerotic activity. Definition of this oruR locus and its effects upon OAcT activity provide evidence that control of ornithine levels in P. aeruginosa may have a significant impact upon how the cell is able to monitor and regulate the use of arginine and glutamate as sources of either carbon or nitrogen.The versatility with which Pseudomonas aeruginosa PAO1 is able to utilize a wide variety of compounds as sole carbon and nitrogen sources is manifest in the complex and intricate nature of its arginine metabolism (4, 11) (Fig. 1). Unlike the situation in enteric bacteria, where the entire arginine biosynthetic regulon is controlled by a single arginine repressor (9), only two of the genes that specifically relate to arginine biosynthesis in P. aeruginosa, namely, argF and argD, have been shown to be regulated by arginine (4,11,27). Significantly, perhaps, both these genes encode enzymes (anabolic ornithine transcarbamylase [aOTCase] [argF] and ornithine aminotransferase [OAT] [argD]) that catalyze important branch points in arginine metabolism (Fig.

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The plasmid-encoded urease gene cluster of the family Enterobacteriaceae is positively regulated by UreR, a member of the AraC family of transcriptional activators

Cited by 53 publications

References 50 publications

Association of the Urease Gene with Enterohemorrhagic Escherichia coli Strains Irrespective of Their Serogroups

Association of the Urease Gene with Enterohemorrhagic Escherichia coli Strains Irrespective of Their Serogroups

Differential regulation of the Proteus mirabilis urease gene cluster by UreR and H-NS

Regulation of ornithine utilization in Pseudomonas aeruginosa (PAO1) is mediated by a transcriptional regulator, OruR

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