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 Finnie, C.
Right arrow Articles by Downie, J. A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Finnie, C.
Right arrow Articles by Downie, J. A.

 Previous Article  |  Next Article 

J Bacteriol, April 1998, p. 1691-1699, Vol. 180, No. 7
0021-9193/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.

Characterization of Rhizobium leguminosarum Exopolysaccharide Glycanases That Are Secreted via a Type I Exporter and Have a Novel Heptapeptide Repeat Motif

Christine Finnie,dagger Angeles Zorreguieta, Nigel M. Hartley, and J. Allan Downie*

John Innes Centre, Norwich NR7 4UH, United Kingdom

Received 30 September 1997/Accepted 22 January 1998

The prsDE genes encode a type I protein secretion system required for the secretion of the nodulation protein NodO and at least three other proteins from Rhizobium leguminosarum bv. viciae. At least one of these proteins was predicted to be a glycanase involved in processing of bacterial exopolysaccharide (EPS). Two strongly homologous genes (plyA and plyB) were identified as encoding secreted proteins with polysaccharide degradation activity. Both PlyA and PlyB degrade EPS and carboxymethyl cellulose (CMC), and these extracellular activities are absent in a prsD (protein secretion) mutant. The plyA gene is upstream of prsD but appears to be expressed at a very low level (if at all) in cultured bacteria. A plyB::Tn5 mutant has a very large reduction in degradation of EPS and CMC. Cultures of plyB mutants contained an increased ratio of EPS repeat units to reducing ends, indicating that the EPS was present in a longer-chain form, and this correlated with a significant increase in culture viscosity. Thus, PlyB may play a role in processing of EPS. Analysis of the symbiotic properties of a plyA plyB double mutant revealed that these genes are not required for symbiotic nitrogen fixation and that nodulation was not significantly affected. PlyA and PlyB are similar to bacterial and fungal polysaccharide lyases; they contain 10 copies of what we propose as a novel heptapeptide repeat motif that may constitute a fold similar to that found in the family of extracellular pectate lyases. PlyA and PlyB lack the Ca2+-binding RTX nonapeptide repeat motifs usually found in proteins secreted via type I systems. We propose that PlyA and PlyB are members of a new family of proteins secreted via type I secretion systems and that they are involved in processing of EPS.

* Corresponding author. Mailing address: John Innes Centre, Norwich Research Park, Norwich NR7 4UH, United Kingdom. Phone: 1603 452571. Fax: 1603 456844. E-mail: downie{at}bbsrc.ac.uk.

dagger Present address: Department of Plant Biology, Royal Vetinary and Agricultural University, 1871 Frederiksberg C, Copenhagen, Denmark.




This article has been cited by other articles:

  • Edwards, A., Frederix, M., Wisniewski-Dye, F., Jones, J., Zorreguieta, A., Downie, J. A. (2009). The cin and rai Quorum-Sensing Regulatory Systems in Rhizobium leguminosarum Are Coordinated by ExpR and CinS, a Small Regulatory Protein Coexpressed with CinI. J. Bacteriol. 191: 3059-3067 [Abstract] [Full Text]  
  • Robledo, M., Jimenez-Zurdo, J. I., Velazquez, E., Trujillo, M. E., Zurdo-Pineiro, J. L., Ramirez-Bahena, M. H., Ramos, B., Diaz-Minguez, J. M., Dazzo, F., Martinez-Molina, E., Mateos, P. F. (2008). Rhizobium cellulase CelC2 is essential for primary symbiotic infection of legume host roots. Proc. Natl. Acad. Sci. USA 105: 7064-7069 [Abstract] [Full Text]  
  • Glenn, S. A., Gurich, N., Feeney, M. A., Gonzalez, J. E. (2007). The ExpR/Sin Quorum-Sensing System Controls Succinoglycan Production in Sinorhizobium meliloti. J. Bacteriol. 189: 7077-7088 [Abstract] [Full Text]  
  • Posadas, D. M., Martin, F. A., Sabio y Garcia, J. V., Spera, J. M., Delpino, M. V., Baldi, P., Campos, E., Cravero, S. L., Zorreguieta, A. (2007). The TolC Homologue of Brucella suis Is Involved in Resistance to Antimicrobial Compounds and Virulence. Infect. Immun. 75: 379-389 [Abstract] [Full Text]  
  • Staehelin, C., Forsberg, L. S., D'Haeze, W., Gao, M.-Y., Carlson, R. W., Xie, Z.-P., Pellock, B. J., Jones, K. M., Walker, G. C., Streit, W. R., Broughton, W. J. (2006). Exo-Oligosaccharides of Rhizobium sp. Strain NGR234 Are Required for Symbiosis with Various Legumes.. J. Bacteriol. 188: 6168-6178 [Abstract] [Full Text]  
  • Russo, D. M., Williams, A., Edwards, A., Posadas, D. M., Finnie, C., Dankert, M., Downie, J. A., Zorreguieta, A. (2006). Proteins Exported via the PrsD-PrsE Type I Secretion System and the Acidic Exopolysaccharide Are Involved in Biofilm Formation by Rhizobium leguminosarum.. J. Bacteriol. 188: 4474-4486 [Abstract] [Full Text]  
  • Ausmees, N., Jacobsson, K., Lindberg, M. (2001). A unipolarly located, cell-surface-associated agglutinin, RapA, belongs to a family of Rhizobium-adhering proteins (Rap) in Rhizobium leguminosarum bv. trifolii. Microbiology 147: 549-559 [Abstract] [Full Text]  
  • Bittinger, M. A., Handelsman, J. (2000). Identification of Genes in the RosR Regulon of Rhizobium etli. J. Bacteriol. 182: 1706-1713 [Abstract] [Full Text]  
  • Zorreguieta, A., Finnie, C., Downie, J. A. (2000). Extracellular Glycanases of Rhizobium leguminosarum Are Activated on the Cell Surface by an Exopolysaccharide-Related Component. J. Bacteriol. 182: 1304-1312 [Abstract] [Full Text]  
  • Perret, X., Staehelin, C., Broughton, W. J. (2000). Molecular Basis of Symbiotic Promiscuity. Microbiol. Mol. Biol. Rev. 64: 180-201 [Abstract] [Full Text]  
  • Svanem, B. I. G., Skjåk-Bræk, G., Ertesvåg, H., Valla, S. (1999). Cloning and Expression of Three New Azotobacter vinelandii Genes Closely Related to a Previously Described Gene Family Encoding Mannuronan C-5-Epimerases. J. Bacteriol. 181: 68-77 [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»