pJM1 Plasmid-Mediated Iron Transport-Virulence System of Vibrio anguillarum

2014 ◽  
pp. 451-461
Author(s):  
Jorge H. Crosa
Keyword(s):  
Iron Transport ◽  
Vibrio Anguillarum

scholarly journals The Overlapping angB and angG Genes Are Encoded within the trans-Acting Factor Region of the Virulence Plasmid in Vibrio anguillarum: Essential Role in Siderophore Biosynthesis

2000 ◽  
Vol 182 (23) ◽  
pp. 6762-6773 ◽  
Author(s):  
Timothy J. Welch ◽  
Sunghee Chai ◽  
Jorge H. Crosa
Keyword(s):  
Iron Transport ◽  
Vibrio Anguillarum ◽  
Site Directed Mutagenesis ◽  
Virulence Plasmid ◽  
Dihydroxybenzoic Acid ◽  
Lyase Activity ◽  
Carboxy Terminal ◽  
Regulatory Functions ◽  
Maximal Expression

Products encoded in the trans-acting factor (TAF) region are necessary for the biosynthesis of anguibactin and for maximal expression of iron transport and biosynthesis genes in the plasmid-encoded iron-scavenging system of Vibrio anguillarum. Here we identify angB, a locus located in the TAF region, which encodes products essential for anguibactin biosynthesis. We demonstrate that a 287-amino-acid polypeptide, encoded by angB and designated AngB, has an isochorismate lyase activity necessary for the synthesis of 2,3-dihydroxybenzoic acid, an anguibactin biosynthesis intermediate. Complementation of variousangB mutations provided evidence that an additional, overlapping gene exists at this locus. This second gene, designatedangG, also has an essential biosynthetic function. TheangG gene directs the expression of three polypeptides when overexpressed in Escherichia coli, all of which are translated in the same frame as AngB. The results of site-directed mutagenesis and in vivo phosphorylation experiments suggest that the carboxy-terminal end of AngB and the AngG polypeptide(s) function as aryl carrier proteins involved in the assembly of the anguibactin molecule. Our results also show that the regulatory functions of the TAF are encoded in a region, TAFr, which is distinct from and independent of the angB and angG genes.

scholarly journals Transcription Termination within the Iron Transport-Biosynthesis Operon of Vibrio anguillarum Requires an Antisense RNA

2007 ◽  
Vol 189 (9) ◽  
pp. 3479-3488 ◽  
Author(s):  
Michiel Stork ◽  
Manuela Di Lorenzo ◽  
Timothy J. Welch ◽  
Jorge H. Crosa
Keyword(s):  
Antisense Rna ◽  
Iron Transport ◽  
Vibrio Anguillarum ◽  
Transcriptional Terminator ◽  
S1 Nuclease ◽  
Polycistronic Mrna ◽  
S1 Nuclease Mapping ◽  
Nuclease Mapping ◽  
Siderophore Transport

ABSTRACT The iron transport-biosynthesis (ITB) operon in Vibrio anguillarum includes four genes for ferric siderophore transport, fatD, -C, -B, and -A, and two genes for siderophore biosynthesis, angR and angT. This cluster plays an important role in the virulence mechanisms of this bacterium. Despite being part of the same polycistronic mRNA, the relative levels of transcription for the fat portion and for the whole ITB message differ profoundly, the levels of the fat transcript being about 17-fold higher. Using S1 nuclease mapping, lacZ transcriptional fusions, and in vitro studies, we were able to show that the differential gene expression within the ITB operon is due to termination of transcription between the fatA and angR genes, although a few transcripts proceeded beyond the termination site to the end of this operon. This termination process requires a 427-nucleotide antisense RNA that spans the intergenic region and acts as a novel transcriptional terminator.

scholarly journals Novel Role of the Lipopolysaccharide O1 Side Chain in Ferric Siderophore Transport and Virulence of Vibrio anguillarum

2005 ◽  
Vol 73 (9) ◽  
pp. 5864-5872 ◽  
Author(s):  
Timothy J. Welch ◽  
Jorge H. Crosa
Keyword(s):  
Iron Transport ◽  
Vibrio Anguillarum ◽  
Fish Host ◽  
Side Chain ◽  
Reading Frame ◽  
Transposon Insertion ◽  
Protein Receptor ◽  
Defective Mutant ◽  
Concomitant Reduction ◽  
Siderophore Transport

ABSTRACTFrom a library of approximately 20,000 transposon mutants, we have identified mutants affected in chromosomal genes involved in synthesis of the siderophore anguibactin, as well as in ferric anguibactin utilization. Genetic and sequence analyses of one such transport-defective mutant revealed that the transposon insertion occurred in an open reading frame (ORF) with homology tormlC, a dTDP-rhamnose biosynthetic gene. This ORF resides within a cluster of four ORFs, all of which are predicted to function in the biosynthesis of this O side chain precursor. The same phenotype was seen in a mutant obtained by allelic exchange inrmlD, another ORF in this dTDP-rhamnose biosynthetic cluster. This mutation could be complemented with the wild-typermlDgene, restoring both production of the O1 antigen side chain and ferric anguibactin transport. Presence of the O1 side chain was crucial for the resistance ofVibrio anguillarumto the bactericidal action of nonimmune serum from the fish host. Surprisingly, further analysis demonstrated that these mutations were pleiotropic, leading to a dramatic decrease in the levels of FatA, the outer membrane protein receptor for ferric anguibactin transport, and a concomitant reduction in iron transport. Thus, our results in this work demonstrate that the lipopolysaccharide O1 side chain is required for the operation of two critical virulence factors inV. anguillarum: serum resistance and anguibactin-mediated iron transport. These factors allowV. anguillarumto survive in serum and multiply in the iron-limiting milieu of the host vertebrate.

scholarly journals Molecular characterization of the iron transport system mediated by the pJM1 plasmid in Vibrio anguillarum 775.

1991 ◽  
Vol 266 (35) ◽  
pp. 23829-23833
Author(s):  
W.L. Köster ◽  
L.A. Actis ◽  
L.S. Waldbeser ◽  
M.E. Tolmasky ◽  
J.H. Crosa
Keyword(s):  
Molecular Characterization ◽  
Transport System ◽  
Iron Transport ◽  
Vibrio Anguillarum

scholarly journals Two tonB Systems Function in Iron Transport in Vibrio anguillarum, but Only One Is Essential for Virulence

2004 ◽  
Vol 72 (12) ◽  
pp. 7326-7329 ◽  
Author(s):  
Michiel Stork ◽  
Manuela Di Lorenzo ◽  
Susana Mouriño ◽  
Carlos R. Osorio ◽  
Manuel L. Lemos ◽  
...  
Keyword(s):  
Marine Fish ◽  
Iron Transport ◽  
Vibrio Anguillarum ◽  
Iron Limitation ◽  
Fish Pathogen

ABSTRACT We have identified two functional tonB systems in the marine fish pathogen Vibrio anguillarum, tonB1 and tonB2. Each of the tonB genes is transcribed in an operon with the cognate exbB and exbD genes in response to iron limitation. Only tonB2 is essential for transport of ferric anguibactin and virulence.

The AngR protein and the siderophore anguibactin positively regulate the expression of iron-transport genes in Vibrio anguillarum

1996 ◽  
Vol 22 (1) ◽  
pp. 127-134 ◽  
Author(s):  
Qian Chen ◽  
Anne M. Wertheimer ◽  
Marcelo E. Tolmasky ◽  
Jorge H. Crosa
Keyword(s):  
Iron Transport ◽  
Vibrio Anguillarum

Regulation of the iron transport genes encoded by the pJM1 virulence plasmid in Vibrio anguillarum

1994 ◽  
pp. 491-504 ◽  
Author(s):  
Jorge H. Crosa ◽  
Luis A. Actis ◽  
Patricia Salinas ◽  
Marcelo E. Tolmasky ◽  
Lillian S. Waldbeser
Keyword(s):  
Iron Transport ◽  
Vibrio Anguillarum ◽  
Virulence Plasmid

scholarly journals A Nonribosomal Peptide Synthetase with a Novel Domain Organization Is Essential for Siderophore Biosynthesis in Vibrio anguillarum

2004 ◽  
Vol 186 (21) ◽  
pp. 7327-7336 ◽  
Author(s):  
Manuela Di Lorenzo ◽  
Sophie Poppelaars ◽  
Michiel Stork ◽  
Maho Nagasawa ◽  
Marcelo E. Tolmasky ◽  
...  
Keyword(s):  
Iron Transport ◽  
Consensus Sequence ◽  
Vibrio Anguillarum ◽  
Gene Promoter ◽  
Nonribosomal Peptide Synthetase ◽  
Transposase Gene ◽  
Nonribosomal Peptide ◽  
Peptide Synthetase ◽  
Fur Protein ◽  
Iron Analysis

ABSTRACT Anguibactin, a siderophore produced by Vibrio anguillarum, is synthesized via a nonribosomal peptide synthetase (NRPS) mechanism. We have identified a gene from the V. anguillarum plasmid pJM1 that encodes a 78-kDa NRPS protein termed AngM, which is essential in the biosynthesis of anguibactin. The predicted AngM amino acid sequence shows regions of homology to the consensus sequence for the peptidyl carrier protein (PCP) and the condensation (C) domains of NRPSs, and curiously, these two domains are not associated with an adenylation (A) domain. Substitution by alanine of the serine 215 in the PCP domain and of histidine 406 in the C domain of AngM results in an anguibactin-deficient phenotype, underscoring the importance of these two domains in the function of this protein. The mutations in angM that affected anguibactin production also resulted in a dramatic attenuation of the virulence of V. anguillarum 775, highlighting the importance of this gene in the establishment of a septicemic infection in the vertebrate host. Transcription of the angM gene is initiated at an upstream transposase gene promoter that is repressed by the Fur protein in the presence of iron. Analysis of the sequence at this promoter showed that it overlaps the iron transport-biosynthesis promoter and operates in the opposite direction.

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