An extracellular serine protease produced by Vibrio vulnificus NCIMB 2137, a metalloprotease-gene negative strain isolated from a diseased eel.
Vibrio vulnificus is a ubiquitous estuarine microorganism but causes fatal systemic infections in immunocompromised humans, cultured eels or shrimps. An extracellular metalloprotease VVP/VvpE has been reported to be a potential virulence factor of the bacterium; however, a few strains isolated from a diseased eel or shrimp were recently found to produce a serine protease termed VvsA, but not VVP/VvpE. In the present study, we found that these strains had lost the 80 kb genomic region including the gene encoding VVP/VvpE. We also purified VvsA from the culture supernatant through ammonium sulfate fractionation, gel filtration and ion-exchange column chromatography, and the enzyme was demonstrated to be a chymotrypsin-like protease, as well as those from some vibrios. The gene vvsA was shown to constitute an operon with a downstream gene vvsB, and several Vibrio species were found to have orthologues of vvsAB. These findings indicate that the genes vvp/vvpE and vvsAB might be mobile genetic elements.
Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Tsushima-Naka, Kita-Ku, Okayama, 700-8530, Japan. miyoshi@pharm.okayama-u.ac.jp
Shin-Ichi
S
Miyoshi
Jiyou
J
Wang
Keizo
K
Katoh
Mitsutoshi
M
Senoh
Tamaki
T
Mizuno
Yoko
Y
Maehara
D000818:Animals; D005591:Chemical Fractionation; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004524:Eels / Q000382:microbiology*; D005798:Genes, Bacterial; D020071:Interspersed Repetitive Sequences; D008969:Molecular Sequence Data; D009876:Operon; D017422:Sequence Analysis, DNA; D057057:Serine Proteases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D014735:Vibrio Infections / Q000382:microbiology / Q000662:veterinary; D041261:Vibrio vulnificus / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification
D004269:DNA, Bacterial; D057057:Serine Proteases