Iron uptake system medicated by Vibrio anguillarum plasmid pJM1

Abstract

Plasmid pJM1 from an invasive strain of Vibrio angiuillarum mediates an ironsequestering system that is associated with the ability of this bacterium to cause septicemia in marine fishes. This plasmid-mediated iron uptake system was analyzed by using mutations caused by transposon Tnl. Restriction endonuclease analysis of iron uptake-deficient and-proficient derivatives generated by insertion of Tnl and molecular cloning experiments permitted us to localize the plasmid regions involved in the process of iron sequestration to a stretch of about 20 kilobase pairs. In addition, the existence of two plasmid-mediated components involved in the process of iron uptake in V. anguillarium was defined: a diffusible substance which functions as a siderophore and a nondiffusible receptor for complexes of iron-siderophore, which we have tentatively identified as the pJM1 plasmid-mediated outer membrane protein OM2 of V. angiuillarium.

A comprehensive review of Vibrio (Listonella) anguillarum: ecology, pathology and prevention

“…The pJM1 plasmid has been sequenced in full by Di Lorenzo et al (2003). Inadequate iron concentration within the V. anguillarum cell promotes pJM1 plasmid syntheses of the diffusible, iron-chelating siderophore 'anguibactin' (Actis et al 1985(Actis et al , 1986) and its respective iron-siderophore complex outer-membrane protein receptor 'OM2' (Crosa & Hodges 1981) for iron acquisition into the cell (Walter et al 1983;Actis et al 1985). Vibrio anguillarum is able to maintain the assembly of its outer-membrane proteins under viable conditions regardless of growth medium or environmental circumstances (Buckley et al 1981).…”

Characterization and regulation of the expression of FatB, an iron transport protein encoded by the pJM1 virulence plasmid

“…Bioassays were carried out basically as described previously (Walter et aL, 1983). Portions of supernatant (10 !~1) from a culture of the wild-type V. anguillarum strain grown in irondepleted CM9 minimal medium were spotted on filter paper disks placed on top of iron-depleted CM9 minimal medium containing 0.7% agarose and seeded with the V. anguillarum strains to be tested and the plates were incubated at 22°C for 48h.…”

Two ABC transporter systems participate in siderophore transport in the marine pathogenVibrio anguillarum775 (pJM1)

“…+, growth À, no growth. CC9-16, 775(pJM1) derivative of a Tn1 insertion mutant able to utilize ferric-anguibactin complexes but unable to synthesize anguibactin (Walter et al, 1983).…”

“…+, growth; À, no growth; -*, a weak halo was observed after 48-h incubation, possibly due to overexpression of fatE from the Ptac promoter in pMMB208. H775-3, pJM1-cured strain of 775 (pJM1); CC9-16, 775(pJM1) derivative of a Tn1 insertion mutant able to utilize ferric-anguibactin complexes but unable to synthesize anguibactin (Walter et al, 1983).…”