title: Sulfoquinovose synthase - an important enzyme in the N-glycosylation pathway of Sulfolobus acidocaldarius.
abstract: Recently, the Surface (S)-layer glycoprotein of the thermoacidophilic crenarchaeote Sulfolobus acidocaldarius was found to be N-glycosylated with a heterogeneous family of glycans, with the largest having a composition Glc(1)Man(2)GlcNAc(2) plus 6-sulfoquinovose. However, genetic analyses of genes involved in the N-glycosylation process in Crenarchaeota were missing so far. In this study we identify a gene cluster involved in the biosynthesis of sulfoquinovose and important for the assembly of the S-layer N-glycans. A successful markerless in-frame deletion of agl3 resulted in a decreased molecular mass of the S-layer glycoprotein SlaA and the flagellin FlaB, indicating a change in the N-glycan composition. Analyses with nanoLC ES-MS/MS confirmed the presence of only a reduced trisaccharide structure composed of Man(1) GlcNAc(2) , missing the sulfoquinovose, a mannose and glucose. Biochemical studies of the recombinant Agl3 confirmed the proposed function as a UDP-sulfoquinovose synthase. Furthermore, S. acidocaldarius cells lacking agl3 had a significantly lower growth rate at elevated salt concentrations compared with the background strain, underlining the importance of the N-glycosylation to maintain an intact and stable cell envelope, to enable the survival of S. acidocaldarius in its extreme environment.
authors: Molecular Biology of Archaea, Max-Planck Institute for terrestrial Microbiology, Karl-von-Frisch-Strasse 10, 35043 Marburg.
authors: Benjamin H
authors: BH
authors: Meyer
authors: Behnam
authors: B
authors: Zolghadr
authors: Elham
authors: E
authors: Peyfoon
authors: Martin
authors: M
authors: Pabst
authors: Maria
authors: M
authors: Panico
authors: Howard R
authors: HR
authors: Morris
authors: Stuart M
authors: SM
authors: Haslam
authors: Paul
authors: P
authors: Messner
authors: Christina
authors: C
authors: Schäffer
authors: Anne
authors: A
authors: Dell
authors: Sonja-Verena
authors: SV
authors: Albers
mesh_terms: D019843:Archaeal Proteins / Q000378:metabolism*; D002853:Chromatography, Liquid; D017353:Gene Deletion; D019766:Genes, Archaeal; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism*; D006031:Glycosylation; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D008757:Methylglucosides / Q000096:biosynthesis*; D005810:Multigene Family; D021241:Spectrometry, Mass, Electrospray Ionization; D016945:Sulfolobus acidocaldarius / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D053719:Tandem Mass Spectrometry
chemical_list: D019843:Archaeal Proteins; D008757:Methylglucosides; C009358:sulfoquinovose; D005964:Glucosyltransferases