Analysis of the pesticin receptor from Yersinia pestis: role in iron-deficient growth and possible regulation by its siderophore

Abstract

We have sequenced a region from the pgm locus of Yersinia pestis KIM6؉ that confers sensitivity to the bacteriocin pesticin to certain strains of Escherichia coli and Y. pestis. The Y. pestis sequence is 98% identical to the pesticin receptor from Yersinia enterocolitica and is homologous to other TonB-dependent outer membrane proteins. Y. pestis strains with an in-frame deletion in the pesticin receptor gene (psn) were pesticin resistant and no longer expressed a group of iron-regulated outer membrane proteins, IrpB to IrpD. In addition, this strain as well as a Y. pestis strain with a mutation constructed in the gene (irp2) encoding the 190-kDa iron-regulated protein HMWP2 could not grow at 37؇C in a defined, iron-deficient medium. However, the irp2 mutant but not the psn mutant could be cross-fed by supernatants from various Yersinia cultures grown under iron-deficient conditions. An analysis of the proteins synthesized by the irp2 mutant suggests that HMWP2 may be indirectly required for maximal expression of the pesticin receptor. HMWP2 likely participates in synthesis of a siderophore which may induce expression of the receptor for pesticin and the siderophore.

HmsT, a protein essential for expression of the haemin storage (Hms+) phenotype of Yersinia pestis

“…Plasmids were isolated from either E. coli or Yersinia strains by alkaline lysis (Birnboim & Doly, 1979) and, when necessary, further purified by polyethylene glycol precipitation (Humphreys et al, 1975). Plasmids were transformed into E. coli by a standard CaCI, procedure (Sambrook et al, 1989) or into Yersinia strains by electroporation (Fetherston et al, 1995). Genomic DNA was isolated by a modified lysozyme/SDS/proteinase K procedure (Fetherston et al, 1992).…”

The irp2 and fyuA genes in High Pathogenicity Islands are involved in the pathogenesis of infections caused by avian pathogenic Escherichia coli (APEC)

“…The irp2 gene is the primary marker gene for HPI detection and an iron-regulating gene closely related to virulence (Carniel et al 1996). The fyuA gene influences iron absorption and encodes an outer membrane receptor for Ybt, bacteriocin, and Pasteurella multocida toxin (Fetherston et al 1994, Fetherston et al 1995.…”

Identification of critical amino acid residues in the plague biofilm Hms proteins

“…A standard CaCl 2 protocol was followed to introduce plasmids into E. coli (Sambrook & Russell, 2001). Y. pestis cells were transformed by electroporation as previously described (Fetherston et al, 1995). All plasmid DNA and PCR products used for construction of chromosomal deletion mutants or cloned amino acid substitution mutants were sequenced by Elim Biopharmaceuticals to ensure that the correct mutation had been introduced and no secondary mutations had occurred.…”

“…Electrocompetent cells were made as previously described (Fetherston et al, 1995) from cultures grown at 26 uC in HIB to OD 620 <0?6 and then incubated for 1?5 h with 0?2 % arabinose to induce expression of the Red recombinase (Datsenko & Wanner, 2000). Gene-specific primers (see Table S1, available as supplementary material with the online version of this paper) were used to amplify the cam gene cassette from pKD3.…”