The Vibrio parahaemolyticuspvuA1 gene (formerly termed psuA) encodes a second ferric vibrioferrin receptor that requires tonB2

Abstract

We previously reported that the Vibrio parahaemolyticus pvsABCDE and psuA-pvuABCDE operons are involved in the biosynthesis and transport of its own siderophore, vibrioferrin (VF). Of these, psuA and pvuA encode TonB-dependent outer-membrane proteins (OMPs). Although pvuA was characterized as the ferric vibrioferrin receptor gene, the role of the psuA product remains unknown. In this study, a growth assay of isogenic psuA, pvuA, and psuA-pvuA double-deletion mutants followed by complementation of the double-deletion mutant with psuA or pvuA was used to identify psuA as a gene encoding an OMP involved in the uptake of ferric VF. Thus, psuA and pvuA were renamed pvuA1 and pvuA2, respectively. Moreover, we clarified the TonB specificities of PvuA1 and PvuA2, because V. parahaemolyticus has three sets of the TonB systems. The triple deletion of pvuA1, tonB1, and tonB2, and the double deletion of pvuA2 and tonB2 resulted in the complete loss of growth promotion by VF. This finding indicates that the energy required for PvuA1 and PvuA2 to transport ferric VF across the outer membrane is provided by the TonB2 system and by both the TonB1 and TonB2 systems, respectively.

The Vibrio parahaemolyticus Small RNA RyhB Promotes Production of the Siderophore Vibrioferrin by Stabilizing the Polycistronic mRNA

“…3); however, the growth of those mutants was not fully restored by the addition of vibrioferrin at 20 M (Fig. 3B), the concentration sufficient to restore the growth of the vibrioferrin-deficient mutant VPD5 (52). This might be explained by RyhB also being involved in positive regulation of the uptake and intracellular utilization systems for ferric vibrioferrin.…”

“…S1 in the supplemental material for sequence details]) listed in Table 1 were constructed by double-crossover allelic exchange using the R6K-ori suicide vector pXAC623 (55). DNA fragments with deletions in ryhB, hfq, and the pvsOp 5=-UTR and with complementary replacement in ryhB and the pvsOp 5=-UTR were prepared by PCR-driven overlap extension (58), as previously described (52). The PCR fragments were digested with appropriate restriction enzymes and cloned into pXAC623.…”

“…The Fur-regulated gene cluster involved in the vibrioferrin-mediated iron acquisition system is composed of 2 divergent operons that contain pvsABCDE (pvsABDE, vibrioferrin biosynthesis genes; pvsC, vibrioferrin exporter gene) (Fig. 1A) and pvuA1-A2-BCDE (pvuA1 and pvuA2, outer membrane receptor genes for ferric vibrioferrin; pvuBCDE, ABC transport system genes for ferric vibrioferrin) (50)(51)(52). In this study, we found that the production of vibrioferrin greatly decreased in the V. parahaemolyticus ryhB deletion mutant relative to the wild-type parental strain.…”

Identification and Characterization of an Outer Membrane Receptor Gene in <i>Acinetobacter baumannii</i> Required for Utilization of Desferricoprogen, Rhodotorulic Acid, and Desferrioxamine B as Xenosiderophores

“…13,30) In contrast, little is known about multiple receptors specific to an inherent siderophore, with the exception of the type 1 ferric pyoverdine receptors, FpvA and FpvB, in P. aeruginosa 35) and the ferric vibrioferrin receptors, PvuA1 and PvuA2, in Vibrio parahaemolyticus. 36) Considering that A. baumannii normally inhabits soil and water surroundings, utilization of desferricoprogen, rhodotorulic acid, and desferrioxamine B may represent one of the strategies that the bacterium has adopted to compete with other neighboring microorganisms for survival and proliferation within its various niches, and promote its opportunities of gaining access to human host. In this context, it is possible that acinetobactin as the cognate siderophore in A. baumannii plays a larger role in acquiring iron in the human host rather than in the natural environmentt, because acinetobactin was reported to be able to capture iron from transferrin and lactoferrin as the main iron sources in human host.…”

Identification and characterization of Aeromonas hydrophila genes encoding the outer membrane receptor of ferrioxamine B and an AraC-type transcriptional regulator

“…Deletion mutants were generated by allelic exchange using the R6K-ori suicide vector pXAC623, as described previously. 16,21) DNA fragments carrying deletions in the A. hydrophila desA, desB, desR, and lacZ (AHA_4101) genes were prepared by PCR-driven overlap extension 22,23) using two primer sets for each gene (DesA1-4, DesB1-4, DesR1-4, and LacZ1-4, respectively). The fragments were digested using XbaI and were ligated into XbaI-digested pXAC623.…”