Previous Article | Next Article ![]()
J. Bacteriol., Nov 1997, 6994-7003, Vol 179, No. 22
M Sandkvist, LO Michel, LP Hough, VM Morales, M Bagdasarian, M Koomey, VJ DiRita and M Bagdasarian
The general secretion pathway (GSP) of Vibrio cholerae is required for
secretion of proteins including chitinase, enterotoxin, and protease
through the outer membrane. In this study, we report the cloning and
sequencing of a DNA fragment from V. cholerae, containing 12 open reading
frames, epsC to -N, which are similar to GSP genes of Aeromonas, Erwinia,
Klebsiella, Pseudomonas, and Xanthomonas spp. In addition to the two
previously described genes, epsE and epsM (M. Sandkvist, V. Morales, and M.
Bagdasarian, Gene 123: 81-86, 1993; L. J. Overbye, M. Sandkvist, and M.
Bagdasarian, Gene 132:101-106, 1993), it is shown here that epsC, epsF,
epsG, and epsL also encode proteins essential for GSP function. Mutations
in the eps genes result in aberrant outer membrane protein profiles, which
indicates that the GSP, or at least some of its components, is required not
only for secretion of soluble proteins but also for proper outer membrane
assembly. Several of the Eps proteins have been identified by use of the T7
polymerase-promoter system in Escherichia coli. One of them, a pilin- like
protein, EpsG, was analyzed also in V. cholerae and found to migrate as two
bands on polyacrylamide gels, suggesting that in this organism it might be
processed or otherwise modified by a prepilin peptidase. We believe that
TcpJ prepilin peptidase, which processes the subunit of the
toxin-coregulated pilus, TcpA, is not involved in this event. This is
supported by the observations that apparent processing of EpsG occurs in a
tcpJ mutant of V. cholerae and that, when coexpressed in E. coli, TcpJ
cannot process EpsG although the PilD peptidase from Neisseria gonorrhoeae
can.
Copyright © 1997, American Society for Microbiology
General secretion pathway (eps) genes required for toxin secretion and outer membrane biogenesis in Vibrio cholerae
Oral Infection and Immunity Branch, National Institute of Dental Research, National Institutes of Health, Bethesda, Maryland 20892-4350, USA.
This article has been cited by other articles:
| Appl. Environ. Microbiol. | Infect. Immun. | Eukaryot. Cell |
|---|---|---|
| Mol. Cell. Biol. | J. Virol. | Microbiol. Mol. Biol. Rev. |
| ALL ASM JOURNALS |