Cloning of a Vibrio cholerae vibriobactin gene cluster: identification of genes required for early steps in siderophore biosynthesis

Abstract

Vibrio cholerae secretes the catechol siderophore vibriobactin in response to iron limitation. Vibriobactin is structurally similar to enterobactin, the siderophore produced by Escherichia coli, and both organisms produce 2,3-dihydroxybenzoic acid (DHBA) as an intermediate in siderophore biosynthesis. To isolate and characterize V. cholerae genes involved in vibriobactin biosynthesis, we constructed a genomic cosmid bank of V. cholerae DNA and isolated clones that complemented mutations in E. coli enterobactin biosynthesis genes. V. cholerae homologs of entA, entB, entC, entD, and entE were identified on overlapping cosmid clones. Our data indicate that the vibriobactin genes are clustered, like the E. coli enterobactin genes, but the organization of the genes within these clusters is different. In this paper, we present the organization and sequences of genes involved in the synthesis and activation of DHBA. In addition, a V. cholerae strain with a chromosomal mutation in vibA was constructed by marker exchange. This strain was unable to produce vibriobactin or DHBA, confirming that in V. cholerae VibA catalyzes an early step in vibriobactin biosynthesis.

Genetic organization of an Acinetobacter baumannii chromosomal region harbouring genes related to siderophore biosynthesis and transport

“…The genetic arrangement of this gene cluster, which encodes proteins highly similar to other bacterial proteins involved in DHBA biosynthesis, is the same as that found in the B. subtilis dhbACEB (Rowland et al, 1996) and the V. cholerae vibACEB (Wyckoff et al, 1997) loci. However, the A. baumannii 8399 and B. subtilis loci are transcribed in the same direction as a single polycistronic unit, while the V. cholerae locus is organized in three transcriptional units.…”

“…V. cholerae, which produces vibriobactin in response to iron limitation, also contains a cluster harbouring the DHBA biosynthetic genes. However, these genes are organized as an entACEB cluster in which entC and entE are co-transcribed while entA and entB belong to two independent transcriptional units (Wyckoff et al, 1997).…”

A Phosphopantetheinyl Transferase Homolog Is Essential for Photorhabdus luminescens To Support Growth and Reproduction of the Entomopathogenic Nematode Heterorhabditis bacteriophora

“…3). NgrA is most similar to the Ppant transferases EntD from Salmonella enterica serovar Typhimurium and E. coli and VibD from Vibrio cholerae, which are required for the biosynthesis of the catechol siderophores enterobactin (16,39) and vibriobactin (54), respectively (residues identical to NgrA are shaded). Ppant transferases transfer the Ppant moiety from coenzyme A to acyl carrier proteins (ACP), aryl carrier proteins, and peptidyl carrier proteins (39).…”

Vibrio cholerae iron transport: haem transport genes are linked to one of two sets of tonB, exbB, exbD genes

“…Henderson and Payne (1993) pHUT10::Tn5f Cm R , pHUT10 with a Tn5 insertion in a non-essential region of DNA with respect to TonB-dependent iron transport Henderson and Payne (1993) pHUT7 Cm R , 6.7 kb Sal I-Hin dIII fragment of pHUT10::Tn5 f cloned into the Sal I/Hin dIII sites of pACYC184 For genes within the TonB1 region, the Xho/Sal I fragments of plasmids containing the aphA-3 disruptions were inserted into the Sal I site of pACSac to form pTONB1::aphA-3, pEXBB1:: aphA-3, pEXBD1::aphA-3, pHUTB::aphA-3, pHUTC::aphA-3 and pHUTD::aphA-3. Each of these plasmids was transferred to CA401 by electroporation, and allelic exchange mutants were isolated by selecting for colonies that were Km R Cm S and sucrose resistant (5% w/v sucrose) as described previously (Wyckoff et al, 1997). Allelic exchange mutants were confirmed by Southern blot analysis (data not shown).…”