The S-layer glycoprotein of the crenarchaeote Sulfolobus acidocaldarius is glycosylated at multiple sites with chitobiose-linked N-glycans

Archaea. 2010 Sep 29;2010:754101. doi: 10.1155/2010/754101.

Abstract

Glycosylation of the S-layer of the crenarchaea Sulfolobus acidocaldarius has been investigated using glycoproteomic methodologies. The mature protein is predicted to contain 31 N-glycosylation consensus sites with approximately one third being found in the C-terminal domain spanning residues L(1004)-Q(1395). Since this domain is rich in Lys and Arg and therefore relatively tractable to glycoproteomic analysis, this study has focused on mapping its N-glycosylation. Our analysis identified nine of the 11 consensus sequence sites, and all were found to be glycosylated. This constitutes a remarkably high glycosylation density in the C-terminal domain averaging one site for each stretch of 30-40 residues. Each of the glycosylation sites observed was shown to be modified with a heterogeneous family of glycans, with the largest having a composition Glc(1)Man(2)GlcNAc(2) plus 6-sulfoquinovose (QuiS), consistent with the tribranched hexasaccharide previously reported in the cytochrome b(558/566) of S. acidocaldarius. S. acidocaldarius is the only archaeal species whose N-glycans are known to be linked via the chitobiose core disaccharide that characterises the N-linked glycans of Eukarya.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Archaeal Proteins / metabolism*
  • Consensus Sequence
  • Disaccharides / metabolism*
  • Glycosylation
  • Mass Spectrometry
  • Membrane Glycoproteins / metabolism*
  • Methylglucosides / metabolism
  • Molecular Sequence Data
  • Polysaccharides / metabolism*
  • Protein Interaction Mapping
  • Proteomics
  • Sulfolobus acidocaldarius / metabolism*

Substances

  • Archaeal Proteins
  • Disaccharides
  • Membrane Glycoproteins
  • Methylglucosides
  • Polysaccharides
  • S-layer proteins
  • sulfoquinovose
  • chitobiose