Identification of bacterial protein O-oligosaccharyltransferases and their glycoprotein substrates

PLoS One. 2013 May 3;8(5):e62768. doi: 10.1371/journal.pone.0062768. Print 2013.


O-glycosylation of proteins in Neisseria meningitidis is catalyzed by PglL, which belongs to a protein family including WaaL O-antigen ligases. We developed two hidden Markov models that identify 31 novel candidate PglL homologs in diverse bacterial species, and describe several conserved sequence and structural features. Most of these genes are adjacent to possible novel target proteins for glycosylation. We show that in the general glycosylation system of N. meningitidis, efficient glycosylation of additional protein substrates requires local structural similarity to the pilin acceptor site. For some Neisserial PglL substrates identified by sensitive analytical approaches, only a small fraction of the total protein pool is modified in the native organism, whereas others are completely glycosylated. Our results show that bacterial protein O-glycosylation is common, and that substrate selection in the general Neisserial system is dominated by recognition of structural homology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acinetobacter / genetics
  • Acinetobacter / metabolism
  • Amino Acid Sequence
  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Glycoproteins / chemistry*
  • Glycoproteins / genetics
  • Glycoproteins / metabolism
  • Glycosylation
  • Glycosyltransferases / chemistry*
  • Glycosyltransferases / genetics
  • Glycosyltransferases / metabolism
  • Markov Chains
  • Molecular Sequence Data
  • Neisseria meningitidis / chemistry*
  • Neisseria meningitidis / enzymology
  • Neisseria meningitidis / genetics
  • O Antigens / chemistry*
  • Protein Processing, Post-Translational*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Substrate Specificity


  • Bacterial Proteins
  • Glycoproteins
  • O Antigens
  • Recombinant Proteins
  • Glycosyltransferases

Grant support

This work was supported by ARC Discovery Project Grant DP110101058 to M.P.J and 486 B.L.S., National Health and Medical Research Council (NHMRC) Program Grant 565526 to M.P.J. and NHMRC CDF APP1031542 to B.L.S. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.