title: The Vibrio parahaemolyticus pvuA1 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.
authors.affiliation: College of Pharmaceutical Sciences, Matsuyama University, Matsuyama, Ehime, Japan. ttanabe@cc.matsuyama-u.ac.jp
authors.forename: Tomotaka
authors.initials: T
authors.lastname: Tanabe
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Funahashi
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Okajima
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakao
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: Katsushiro
authors.initials: K
authors.lastname: Miyamoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tsujibo
authors.forename: Shigeo
authors.initials: S
authors.lastname: Yamamoto
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002951:Citrates / Q000378:metabolism*; D017353:Gene Deletion; D005816:Genetic Complementation Test; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D011760:Pyrrolidinones / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D014736:Vibrio parahaemolyticus / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D002951:Citrates; D008565:Membrane Proteins; D011760:Pyrrolidinones; D011956:Receptors, Cell Surface; C449643:pvuA protein, Vibrio; C057616:tonB protein, Bacteria; C090126:vibrioferrin