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In vitro bacterial polysaccharide biosynthesis: defining the functions of Wzy and Wzz

Abstract

Polysaccharides constitute a major component of bacterial cell surfaces and play critical roles in bacteria–host interactions. The biosynthesis of such molecules, however, has mainly been characterized through in vivo genetic studies, thus precluding discernment of the details of this pathway. Accordingly, we present a chemical approach that enabled reconstitution of the E. coli O-polysaccharide biosynthetic pathway in vitro. Starting with chemically prepared undecaprenyl-diphospho-N-acetyl-D-galactosamine, the E. coli O86 oligosaccharide repeating unit was assembled by means of sequential enzymatic glycosylation. Successful expression of the putative polymerase Wzy using a chaperone coexpression system then allowed demonstration of polymerization in vitro using this substrate. Analysis of more substrates revealed a defined mode of recognition for Wzy toward the lipid moiety. Specific polysaccharide chain length modality was furthermore demonstrated to result from the action of Wzz. Collectively, polysaccharide biosynthesis was chemically reconstituted in vitro, providing a well defined system for further underpinning molecular details of this biosynthetic pathway.

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Figure 1: wzy-dependent pathway of O-polysaccharide biosynthesis (E. coli O86:B7 O-polysaccharide as an example).
Figure 2: In vitro reconstitution of E. coli O86 polysaccharide repeating unit biosynthesis and associated product characterization.
Figure 3: Analysis of the Wzy polymerization reaction with the Und-based donor by SDS-PAGE and visualization with autoradiography.

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References

  1. Robbins, J.B., Schneerson, R., Egan, W.B., Vann, W. & Liu, D.T. Virulence properties of bacterial capsular polysaccharides–unanswered questions. Life Sci. Res. Rep. 16, 115–132 (1980).

    CAS  Google Scholar 

  2. Moxon, E.R. & Kroll, J.S. The role of bacterial polysaccharide capsules as virulence factors. Curr. Top. Microbiol. Immunol. 150, 65–85 (1990).

    CAS  PubMed  Google Scholar 

  3. Finn, A. Bacterial polysaccharide-protein conjugate vaccines. Br. Med. Bull. 70, 1–14 (2004).

    Article  CAS  Google Scholar 

  4. Plotkin, S.A. Vaccines: past, present and future. Nat. Med. 11, S5–S11 (2005).

    Article  CAS  Google Scholar 

  5. Briles, D.E., Paton, J.C., Swiatlo, E. & Crain, M.J. Pneumococcal vaccines. Gram-Positive Pathogens 2nd edn., (ed. Fishetti, V.A.) 289–298 (ASM Press, Washington, DC, 2006).

  6. Westphal, O., Jann, K. & Himmelspach, K. Chemistry and immunochemistry of bacterial lipopolysaccharides as cell wall antigens and endotoxins. Prog. Allergy 33, 9–39 (1983).

    CAS  PubMed  Google Scholar 

  7. Costerton, J.W. et al. Bacterial biofilms in nature and disease. Annu. Rev. Microbiol. 41, 435–464 (1987).

    Article  CAS  Google Scholar 

  8. Jenkinson, H.F. Adherence and accumulation of oral streptococci. Trends Microbiol. 2, 209–212 (1994).

    Article  CAS  Google Scholar 

  9. Sahly, H., Keisari, Y., Crouch, E., Sharon, N. & Ofek, I. Recognition of bacterial surface polysaccharides by lectins of the innate immune system and its contribution to defense against infection: the case of pulmonary pathogens. Infect. Immun. 76, 1322–1332 (2008).

    Article  CAS  Google Scholar 

  10. Holst, O. The structures of core regions from enterobacterial lipopolysaccharides-an update. FEMS Microbiol. Lett. 271, 3–11 (2007).

    Article  CAS  Google Scholar 

  11. Raetz, C.R.H. & Whitfield, C. Lipopolysaccharide endotoxins. Annu. Rev. Biochem. 71, 635–700 (2002).

    Article  CAS  Google Scholar 

  12. Whitfield, C., Amor, P.A. & Koplin, R. Modulation of the surface architecture of gram-negative bacteria by the action of surface polymer:lipid A-core ligase and by determinants of polymer chain length. Mol. Microbiol. 23, 629–638 (1997).

    Article  CAS  Google Scholar 

  13. Nesper, J. et al. Characterization of Vibrio cholerae O1 El tor galU and galE mutants: influence on lipopolysaccharide structure, colonization, and biofilm formation. Infect. Immun. 69, 435–445 (2001).

    Article  CAS  Google Scholar 

  14. Raetz, C.R., Reynolds, C.M., Trent, M.S. & Bishop, R.E. Lipid A modification systems in gram-negative bacteria. Annu. Rev. Biochem. 76, 295–329 (2007).

    Article  CAS  Google Scholar 

  15. Abeyrathne, P.D. & Lam, J.S. WaaL of Pseudomonas aeruginosa utilizes ATP in in vitro ligation of O antigen onto lipid A-core. Mol. Microbiol. 65, 1345–1359 (2007).

    Article  CAS  Google Scholar 

  16. Whitfield, C. Biosynthesis and assembly of capsular polysaccharides in Escherichia coli. Annu. Rev. Biochem. 75, 39–68 (2006).

    Article  CAS  Google Scholar 

  17. Guo, H., Yi, W., Song, J.K. & Wang, P.G. Current understanding on biosynthesis of microbial polysaccharides. Curr. Top. Med. Chem. 8, 141–151 (2008).

    Article  CAS  Google Scholar 

  18. Lehrer, J., Vigeant, K.A., Tatar, L.D. & Valvano, M.A. Functional characterization and membrane topology of Escherichia coli WecA, a sugar-phosphate transferase initiating the biosynthesis of enterobacterial common antigen and O-antigen lipopolysaccharide. J. Bacteriol. 189, 2618–2628 (2007).

    Article  CAS  Google Scholar 

  19. Al-Dabbagh, B., Mengin-Lecreulx, D. & Bouhss, A. Purification and characterization of the bacterial UDP-GlcNAc:undecaprenyl-phosphate GlcNAc-1-phosphate transferase WecA. J. Bacteriol. 190, 7141–7146 (2008).

    Article  CAS  Google Scholar 

  20. Liu, D., Cole, R.A. & Reeves, P.R. An O-antigen processing function for Wzx (RfbX): a promising candidate for O-unit flippase. J. Bacteriol. 178, 2102–2107 (1996).

    Article  CAS  Google Scholar 

  21. Robbins, P.W., Bray, D., Dankert, M.A. & Wright, A. Direction of chain growth in polysaccharide synthesis. Science 158, 1536–1542 (1967).

    Article  CAS  Google Scholar 

  22. Kanegasaki, S. & Wright, A. Mechanism of polymerization of the Salmonella O-antigen: utilization of lipid-linked intermediates. Proc. Natl. Acad. Sci. USA 67, 951–958 (1970).

    Article  CAS  Google Scholar 

  23. Guo, H. et al. Molecular analysis of the O-antigen gene cluster of Escherichia coli O86:B7 and characterization of the chain length determinant gene (wzz). Appl. Environ. Microbiol. 71, 7995–8001 (2005).

    Article  CAS  Google Scholar 

  24. Yi, W. et al. Escherichia coli O86 O-antigen biosynthetic gene cluster and stepwise enzymatic synthesis of human blood group B antigen tetrasaccharide. J. Am. Chem. Soc. 127, 2040–2041 (2005).

    Article  CAS  Google Scholar 

  25. Yi, W. et al. Two different O-polysaccharides from Escherichia coli O86 are produced by different polymerization of the same O-repeating unit. Carbohydr. Res. 341, 100–108 (2006).

    Article  CAS  Google Scholar 

  26. Yi, W. et al. The wbnH gene of Escherichia coli O86:H2 encodes an alpha-1,3-N-acetylgalactosaminyl transferase involved in the O-repeating unit biosynthesis. Biochem. Biophys. Res. Commun. 344, 631–639 (2006).

    Article  CAS  Google Scholar 

  27. Valvano, M.A. Undecaprenyl phosphate recycling comes out of age. Mol. Microbiol. 67, 232–235 (2008).

    Article  CAS  Google Scholar 

  28. Wacker, M. et al. N-linked glycosylation in Campylobacter jejuni and its functional transfer into E. coli. Science 298, 1790–1793 (2002).

    Article  CAS  Google Scholar 

  29. Kowarik, M. et al. N-linked glycosylation of folded proteins by the bacterial oligosaccharyltransferase. Science 314, 1148–1150 (2006).

    Article  CAS  Google Scholar 

  30. Faridmoayer, A., Fentabil, M.A., Mills, D.C., Klassen, J.S. & Feldman, M.F. Functional characterization of bacterial oligosaccharyltransferases involved in O-linked protein glycosylation. J. Bacteriol. 189, 8088–8098 (2007).

    Article  CAS  Google Scholar 

  31. Faridmoayer, A. et al. Extreme substrate promiscuity of the Neisseria oligosaccharyl transferase involved in protein O-glycosylation. J. Biol. Chem. 283, 34596–34604 (2008).

    Article  CAS  Google Scholar 

  32. Al-Dabbagh, B., Blanot, D., Mengin-Lecreulx, D. & Bouhss, A. Preparative enzymatic synthesis of polyprenyl-pyrophosphoryl-N-acetylglucosamine, an essential lipid intermediate for the biosynthesis of various bacterial cell envelope polymers. Anal. Biochem. 391, 163–165 (2009).

    Article  CAS  Google Scholar 

  33. Barrett, D. et al. Analysis of glycan polymers produced by peptidoglycan glycosyltransferases. J. Biol. Chem. 282, 31964–31971 (2007).

    Article  CAS  Google Scholar 

  34. Zhang, Y. et al. Synthesis of heptaprenyl-lipid IV to analyze peptidoglycan glycosyltransferases. J. Am. Chem. Soc. 129, 3080–3081 (2007).

    Article  CAS  Google Scholar 

  35. Daniels, C. & Morona, R. Analysis of Shigella flexneri wzz (Rol) function by mutagenesis and cross-linking: wzz is able to oligomerize. Mol. Microbiol. 34, 181–194 (1999).

    Article  CAS  Google Scholar 

  36. Bengoechea, J.A. et al. Functional characterization of Gne (UDP-N-acetylglucosamine-4-epimerase), Wzz (chain length determinant), and Wzy (O-antigen polymerase) of Yersinia enterocolitica serotype O:8. J. Bacteriol. 184, 4277–4287 (2002).

    Article  CAS  Google Scholar 

  37. Marolda, C.L., Tatar, L.D., Alaimo, C., Aebi, M. & Valvano, M.A. Interplay of the Wzx translocase and the corresponding polymerase and chain length regulator proteins in the translocation and periplasmic assembly of lipopolysaccharide O antigen. J. Bacteriol. 188, 5124–5135 (2006).

    Article  CAS  Google Scholar 

  38. Bastin, D.A., Stevenson, G., Brown, P.K., Haase, A. & Reeves, P.R. Repeat unit polysaccharides of bacteria: a model for polymerization resembling that of ribosomes and fatty acid synthetase, with a novel mechanism for determining chain length. Mol. Microbiol. 7, 725–734 (1993).

    Article  CAS  Google Scholar 

  39. Morona, R., van den Bosch, L. & Manning, P.A. Molecular, genetic, and topological characterization of O-antigen chain length regulation in Shigella flexneri. J. Bacteriol. 177, 1059–1068 (1995).

    Article  CAS  Google Scholar 

  40. Tang, K.H., Guo, H., Yi, W., Tsai, M.D. & Wang, P.G. Investigation of the conformational states of Wzz and the Wzz.O-antigen complex under near-physiological conditions. Biochemistry 46, 11744–11752 (2007).

    Article  CAS  Google Scholar 

  41. Tocilj, A. et al. Bacterial polysaccharide co-polymerases share a common framework for control of polymer length. Nat. Struct. Mol. Biol. 15, 130–138 (2008).

    Article  CAS  Google Scholar 

  42. Larue, K., Kimber, M.S., Ford, R. & Whitfield, C. Biochemical and structural analysis of bacterial O-antigen chain length regulator proteins reveals a conserved quaternary structure. J. Biol. Chem. 284, 7395–7403 (2009).

    Article  CAS  Google Scholar 

  43. Daniels, C., Griffiths, C., Cowles, B. & Lam, J.S. Pseudomonas aeruginosa O-antigen chain length is determined before ligation to lipid A core. Environ. Microbiol. 4, 883–897 (2002).

    Article  CAS  Google Scholar 

  44. Ye, X.Y. et al. Better substrates for bacterial transglycosylases. J. Am. Chem. Soc. 123, 3155–3156 (2001).

    Article  CAS  Google Scholar 

  45. Glover, K.J., Weerapana, E., Numao, S. & Imperiali, B. Chemoenzymatic synthesis of glycopeptides with PglB, a bacterial oligosaccharyl transferase from Campylobacter jejuni. Chem. Biol. 12, 1311–1315 (2005).

    Article  CAS  Google Scholar 

  46. Chen, M.M., Glover, K.J. & Imperiali, B. From peptide to protein: comparative analysis of the substrate specificity of N-linked glycosylation in C. jejuni. Biochemistry 46, 5579–5585 (2007).

    Article  CAS  Google Scholar 

  47. Bigge, J.C. et al. Nonselective and efficient fluorescent labeling of glycans using 2-amino benzamide and anthranilic acid. Anal. Biochem. 230, 229–238 (1995).

    Article  CAS  Google Scholar 

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Acknowledgements

We are grateful to J. Liu (University of North Carolina) for providing the GroES/EL expression vector and helpful discussions of expression conditions. R.W. acknowledges the NIH Predoctoral Trainee Program (T32 GM008512). L.L. acknowledges support from the China Scholarship Council (2007102057). P.G.W. acknowledges the US National Cancer Institute (R01 CA118208), US National Institutes of Health (R01 GM085267), US National Science Foundation (CHE-0616892) and Bill & Melinda Gates Foundation (51946) for financial support.

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Authors

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R.W., W.Y. and P.G.W. designed research. R.W., L.L., W.Y., G.Z., H.E., P.R.S., H.G., J.K.S., E.M., L.C., P.K., X.L., W.H., W.Z., Y.D. and M.L. performed research. L.L., W.Y., G.Z., H.E. and P.G.W. analyzed data. R.W., L.L., W.Y., G.Z. and P.G.W. wrote the paper.

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Correspondence to Peng George Wang.

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Woodward, R., Yi, W., Li, L. et al. In vitro bacterial polysaccharide biosynthesis: defining the functions of Wzy and Wzz. Nat Chem Biol 6, 418–423 (2010). https://doi.org/10.1038/nchembio.351

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