This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplemental material
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 Zuber, B.
Right arrow Articles by Daffé, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Zuber, B.
Right arrow Articles by Daffé, M.

 Previous Article  |  Next Article 

Journal of Bacteriology, August 2008, p. 5672-5680, Vol. 190, No. 16
0021-9193/08/$08.00+0     doi:10.1128/JB.01919-07
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

Direct Visualization of the Outer Membrane of Mycobacteria and Corynebacteria in Their Native State{triangledown} ,{dagger}

Benoît Zuber,1,{ddagger}* Mohamed Chami,2 Christine Houssin,3,4 Jacques Dubochet,1,§ Gareth Griffiths,5 and Mamadou Daffé6,7*

Laboratory of Ultrastructural Analysis, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland,1 M. E. Müller Institute for Structural Biology, Biozentrum, University of Basel, Klingelbergstrasse 70, 4056 CH Basel, Switzerland,2 Institut de Génétique et Microbiologie, Université Paris-Sud, F-91405 Orsay, France,3 Centre National de la Recherche Scientifique, F-91405 Orsay, France,4 EMBL, Postfach 102209, 69117 Heidelberg, Germany,5 Université Paul Sabatier (Toulouse III), Institut de Pharmacologie et de Biologie Structurale (IPBS), 205 Route de Narbonne, 31077 Toulouse cedex 04, France,6 Centre National de la Recherche Scientifique (CNRS), IPBS, Département des Mécanismes Moléculaires des Infections Mycobactériennes, 205 Route de Narbonne, 31077 Toulouse cedex 04, France7

Received 10 December 2007/ Accepted 9 June 2008

The cell envelope of mycobacteria, which include the causative agents of tuberculosis and leprosy, is crucial for their success as pathogens. Despite a continued strong emphasis on identifying the multiple chemical components of this envelope, it has proven difficult to combine its components into a comprehensive structural model, primarily because the available ultrastructural data rely on conventional electron microscopy embedding and sectioning, which are known to induce artifacts. The existence of an outer membrane bilayer has long been postulated but has never been directly observed by electron microscopy of ultrathin sections. Here we have used cryo-electron microscopy of vitreous sections (CEMOVIS) to perform a detailed ultrastructural analysis of three species belonging to the Corynebacterineae suborder, namely, Mycobacterium bovis BCG, Mycobacterium smegmatis, and Corynebacterium glutamicum, in their native state. We provide new information that accurately describes the different layers of the mycobacterial cell envelope and challenges current models of the organization of its components. We show a direct visualization of an outer membrane, analogous to that found in gram-negative bacteria, in the three bacterial species examined. Furthermore, we demonstrate that mycolic acids, the hallmark of mycobacteria and related genera, are essential for the formation of this outer membrane. In addition, a granular layer and a low-density zone typifying the periplasmic space of gram-positive bacteria are apparent in CEMOVIS images of mycobacteria and corynebacteria. Based on our observations, a model of the organization of the lipids in the outer membrane is proposed. The architecture we describe should serve as a reference for future studies to relate the structure of the mycobacterial cell envelope to its function.

* Corresponding author. Mailing address for Benoît Zuber: MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, United Kingdom. Phone: 44 1223 402209. Fax: 44 1223 402310. E-mail: bzuber{at}mrc-lmb.cam.ac.uk. Mailing address for Mamadou Daffé: Université Paul Sabatier (Toulouse III), Institut de Pharmacologie et de Biologie Structurale (IPBS), 205 Route de Narbonne, 31077 Toulouse cedex 04, France. Phone: 33 561 175 569. Fax: 33 561 175 580. E-mail: mamadou.daffe{at}ipbs.fr

{triangledown} Published ahead of print on 20 June 2008.

{dagger} Supplemental material for this article may be found at http://jb.asm.org/.

{ddagger} Present address: MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, United Kingdom.

§ Present address: DEE, Biophore Building, University of Lausanne, 1015 Lausanne, Switzerland.

Journal of Bacteriology, August 2008, p. 5672-5680, Vol. 190, No. 16
0021-9193/08/$08.00+0     doi:10.1128/JB.01919-07
Copyright © 2008, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Leversen, N. A., de Souza, G. A., Malen, H., Prasad, S., Jonassen, I., Wiker, H. G. (2009). Evaluation of signal peptide prediction algorithms for identification of mycobacterial signal peptides using sequence data from proteomic methods. Microbiology 155: 2375-2383 [Abstract] [Full Text]  
  • Provvedi, R., Boldrin, F., Falciani, F., Palu, G., Manganelli, R. (2009). Global transcriptional response to vancomycin in Mycobacterium tuberculosis. Microbiology 155: 1093-1102 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»