This Article
Right arrow Full Text
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 Ciocchini, A. E.
Right arrow Articles by Ugalde, R. A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Ciocchini, A. E.
Right arrow Articles by Ugalde, R. A.

 Previous Article  |  Next Article 

Journal of Bacteriology, November 2004, p. 7205-7213, Vol. 186, No. 21
0021-9193/04/$08.00+0     DOI: 10.1128/JB.186.21.7205-7213.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.

Membrane Topology Analysis of Cyclic Glucan Synthase, a Virulence Determinant of Brucella abortus

Andrés E. Ciocchini, Mara S. Roset, Nora Iñón de Iannino, and Rodolfo A. Ugalde*

Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (IIB-INTECH), Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de General San Martín (CONICET-UNSAM), Buenos Aires, Argentina

Received 12 June 2004/ Accepted 19 July 2004

Brucella abortus cyclic glucan synthase (Cgs) is a 316-kDa (2,831-amino-acid) integral inner membrane protein that is responsible for the synthesis of cyclic ß-1,2-glucan by a novel mechanism in which the enzyme itself acts as a protein intermediate. B. abortus Cgs uses UDP-glucose as a sugar donor and has the three enzymatic activities necessary for synthesis of the cyclic polysaccharide (i.e., initiation, elongation, and cyclization). Cyclic glucan is required in B. abortus for effective host interaction and complete expression of virulence. To gain further insight into the structure and mechanism of action of B. abortus Cgs, we studied the membrane topology of the protein using a combination of in silico predictions, a genetic approach involving the construction of fusions between the cgs gene and the genes encoding alkaline phosphatase (phoA) and ß-galactosidase (lacZ), and site-directed chemical labeling of lysine residues. We found that B. abortus Cgs is a polytopic membrane protein with the amino and carboxyl termini located in the cytoplasm and with six transmembrane segments, transmembrane segments I (residues 419 to 441), II (residues 452 to 474), III (residues 819 to 841), IV (residues 847 to 869), V (residues 939 to 961), and VI (residues 968 to 990). The six transmembrane segments determine four large cytoplasmic domains and three very small periplasmic regions.

* Corresponding author. Mailing address: Instituto de Investigaciones Biotecnológicas, Av. General Paz 5445, San Martín 1650, Provincia de Buenos Aires, Argentina. Phone: (54-11) 4580-7255. Fax: (54-11) 4752-9639. E-mail: rugalde{at}iib.unsam.edu.ar.

Journal of Bacteriology, November 2004, p. 7205-7213, Vol. 186, No. 21
0021-9193/04/$08.00+0     DOI: 10.1128/JB.186.21.7205-7213.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Guidolin, L. S., Ciocchini, A. E., Inon de Iannino, N., Ugalde, R. A. (2009). Functional Mapping of Brucella abortus Cyclic {beta}-1,2-Glucan Synthase: Identification of the Protein Domain Required for Cyclization. J. Bacteriol. 191: 1230-1238 [Abstract] [Full Text]  
  • Ciocchini, A. E., Guidolin, L. S., Casabuono, A. C., Couto, A. S., Inon de Iannino, N., Ugalde, R. A. (2007). A glycosyltransferase with a length-controlling activity as a mechanism to regulate the size of polysaccharides. Proc. Natl. Acad. Sci. USA 104: 16492-16497 [Abstract] [Full Text]  
  • Ciocchini, A. E., Roset, M. S., Briones, G., de Iannino, N. I., Ugalde, R. A. (2006). Identification of active site residues of the inverting glycosyltransferase Cgs required for the synthesis of cyclic {beta}-1,2-glucan, a Brucella abortus virulence factor. Glycobiology 16: 679-691 [Abstract] [Full Text]  
  • Chain, P. S. G., Comerci, D. J., Tolmasky, M. E., Larimer, F. W., Malfatti, S. A., Vergez, L. M., Aguero, F., Land, M. L., Ugalde, R. A., Garcia, E. (2005). Whole-Genome Analyses of Speciation Events in Pathogenic Brucellae. Infect. Immun. 73: 8353-8361 [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»