Journal of Bacteriology, December 2001, p. 6794-6800, Vol. 183, No. 23
0021-9193/01/$04.00+0 DOI: 10.1128/JB.183.23.6794-6800.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544
Received 25 June 2001/Accepted 29 August 2001
The periplasm of Escherichia coli contains many
proteins proposed to have redundant functions in protein folding. Using
depletion analysis, we directly demonstrated that null mutations in
skp and surA, as well as in
degP and surA, result in synthetic
phenotypes, suggesting that Skp, SurA, and DegP are functionally
redundant. The
skp surA::kan
combination has a bacteriostatic effect and leads to filamentation,
while the degP::Tn10
surA::kan combination is bactericidal.
The steady-state levels of several envelope proteins are greatly
reduced upon depletion of a wild-type copy of surA in
both instances. We suggest that the functional redundancy of Skp, SurA,
and DegP lies in the periplasmic chaperone activity. Taken together,
our data support a model in which the periplasm of E.
coli contains parallel pathways for chaperone activity. In
particular, we propose that Skp and DegP are components of the same
pathway and that SurA is a component of a separate pathway. The loss of
either pathway has minimal effects on the cell, while the loss of both
pathways results in the synthetic phenotypes observed.
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 |