JB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Everett, K. D.
Right arrow Articles by Hatch, T. P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Everett, K. D.
Right arrow Articles by Hatch, T. P.

 Previous Article  |  Next Article 

J. Bacteriol., 02 1995, 877-882, Vol 177, No. 4
Copyright © 1995, American Society for Microbiology

Architecture of the cell envelope of Chlamydia psittaci 6BC

KD Everett and TP Hatch
Department of Microbiology and Immunology, University of Tennessee, Memphis 38163.

The cysteine-rich envelope proteins of the elementary body form of chlamydiae are thought to be located in the outer membrane on the basis of their insolubility in the weak anionic detergent N-lauryl sarcosinate (Sarkosyl). We found, however, that the insolubility of the small (EnvA) and the large (EnvB) cysteine-rich proteins of Chlamydia psittaci 6BC in Sarkosyl is dependent on the maintenance of a supramolecular disulfide-cross-linked complex and is unlikely to be a valid indicator of outer membrane location. Consequently, we used other methods to characterize the architecture of the cell envelope of C. psittaci 6BC. We found that disulfide-reduced EnvA, previously shown to be a lipoprotein, segregated into the detergent phase during Triton X- 114 partitioning experiments and was recovered from the membrane fraction of elementary bodies lysed by nondetergent means. In contrast, disulfide-reduced EnvB segregated to the aqueous phase in partitioning experiments and was found in the soluble fraction of elementary bodies lysed in the absence of detergents. The hydrophobic affinity probe 3- (trifluoromethyl)-3-(m-[125I]iodophenyl)-diazirine labeled the major outer membrane protein and EnvA but did not label EnvB. Treatment of intact elementary bodies of C. psittaci with trypsin had no effect on the cysteine-rich proteins, although the major outer membrane protein was partially degraded. On the basis of these and other observations, we propose that EnvA is anchored to the outer membrane by its lipid moiety, with a hydrophilic peptide portion extending into the periplasm, and that EnvB is located exclusively within the periplasm. We further propose that disulfide-cross-linked polymers of EnvB are the functional equivalent of peptidoglycan, forming a disulfide-cross- linked network with the periplasmic domains of EnvA and other membrane proteins, which accounts for the osmotic stability of elementary bodies.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Appl. Environ. Microbiol. Infect. Immun. Eukaryot. Cell
Mol. Cell. Biol. J. Virol. Microbiol. Mol. Biol. Rev.
ALL ASM JOURNALS

Copyright © 1995 by the American Society for Microbiology. All rights reserved.