title: Surface-exposed glycoproteins of hyperthermophilic Sulfolobus solfataricus P2 show a common N-glycosylation profile.
abstract: Cell surface proteins of hyperthermophilic Archaea actively participate in intercellular communication, cellular uptake, and energy conversion to sustain survival strategies in extreme habitats. Surface (S)-layer glycoproteins, the major component of the S-layers in many archaeal species and the best-characterized prokaryotic glycoproteins, were shown to have a large structural diversity in their glycan compositions. In spite of this, knowledge on glycosylation of proteins other than S-layer proteins in Archaea is quite limited. Here, the N-glycosylation pattern of cell-surface-exposed proteins of Sulfolobus solfataricus P2 were analyzed by lectin affinity purification, HPAEC-PAD, and multiple mass spectrometry-based techniques. Detailed analysis of SSO1273, one of the most abundant ABC transporters present in the cell surface fraction of S. solfataricus, revealed a novel glycan structure composed of a branched sulfated heptasaccharide, Hex4(GlcNAc)2 plus sulfoquinovose where Hex is d-mannose and d-glucose. Having one monosaccharide unit more than the glycan of the S-layer glycoprotein of S. acidocaldarius, this is the most complex archaeal glycan structure known today. SSO1273 protein is heavily glycosylated and all 20 theoretical N-X-S/T (where X is any amino acid except proline) consensus sequence sites were confirmed. Remarkably, we show that several other proteins in the surface fraction of S. solfataricus are N-glycosylated by the same sulfated oligosaccharide and we identified 56 N-glycosylation sites in this subproteome.
authors.affiliation: Institute of Protein Biochemistry, National Research Council of Italy, Napoli, Italy.
authors.forename: Gianna
authors.initials: G
authors.lastname: Palmieri
authors.forename: Marco
authors.initials: M
authors.lastname: Balestrieri
authors.forename: Jasna
authors.initials: J
authors.lastname: Peter-Katalinić
authors.forename: Gottfried
authors.initials: G
authors.lastname: Pohlentz
authors.forename: Mosè
authors.initials: M
authors.lastname: Rossi
authors.forename: Immacolata
authors.initials: I
authors.lastname: Fiume
authors.forename: Gabriella
authors.initials: G
authors.lastname: Pocsfalvi
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000737:chemistry / Q000302:isolation & purification*; D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000737:chemistry / Q000302:isolation & purification*; D002240:Carbohydrate Sequence; D002846:Chromatography, Affinity; D006031:Glycosylation; D037102:Lectins / Q000737:chemistry; D013058:Mass Spectrometry; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D025942:Oligosaccharides, Branched-Chain / Q000737:chemistry / Q000302:isolation & purification*; D048229:Sulfolobus solfataricus / Q000737:chemistry*
chemical_list: D018528:ATP-Binding Cassette Transporters; D019843:Archaeal Proteins; D037102:Lectins; D008562:Membrane Glycoproteins; D025942:Oligosaccharides, Branched-Chain