title: Glycosylation of wall teichoic acid in Staphylococcus aureus by TarM.
abstract: Wall teichoic acid (WTA) glycopolymers are major constituents of cell envelopes in Staphylococcus aureus and related gram-positive bacteria with important roles in cell wall maintenance, susceptibility to antimicrobial molecules, biofilm formation, and host interaction. Most S. aureus strains express polyribitol phosphate WTA substituted with D-alanine and N-acetylglucosamine (GlcNAc). WTA sugar modifications are highly variable and have been implicated in bacteriophage susceptibility and immunogenicity, but the pathway and enzymes of staphylococcal WTA glycosylation have remained unknown. Revisiting the structure of S. aureus RN4220 WTA by NMR analysis revealed the presence of canonical polyribitol phosphate WTA bearing only alpha-linked GlcNAc substituents. A RN4220 transposon mutant resistant to WTA-dependent phages was identified and shown to produce altered WTA, which exhibited faster electrophoretic migration and lacked completely the WTA alpha-GlcNAc residues. Disruption of a gene of unknown function, renamed tarM, was responsible for this phenotype. Recombinant TarM was capable of glycosylating WTA in vitro in a UDP-GlcNAc-dependent manner, thereby confirming its WTA GlcNAc-transferase activity. Deletion of the last seven amino acids from the C terminus abolished the activity of TarM. tarM-related genes were found in the genomes of several WTA-producing bacteria, suggesting that TarM-mediated WTA glycosylation is a general pathway in gram-positive bacteria. Our study represents a basis for dissecting the biosynthesis and function of glycosylated WTA in S. aureus and other bacteria.
authors.affiliation: Division of Cellular and Molecular Microbiology, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Elfriede-Aulhorn-Strasse 6, D-72076 Tübingen, Germany.
authors.forename: Guoqing
authors.initials: G
authors.lastname: Xia
authors.forename: Lisa
authors.initials: L
authors.lastname: Maier
authors.forename: Patricia
authors.initials: P
authors.lastname: Sanchez-Carballo
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.forename: Michael
authors.initials: M
authors.lastname: Otto
authors.forename: Otto
authors.initials: O
authors.lastname: Holst
authors.forename: Andreas
authors.initials: A
authors.lastname: Peschel
mesh_terms: D000117:Acetylglucosamine / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002473:Cell Wall / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D004251:DNA Transposable Elements / Q000235:genetics; D055785:Gene Knockdown Techniques; D006031:Glycosylation; D016695:Glycosyltransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D009154:Mutation; D011134:Polysaccharides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion; D013211:Staphylococcus aureus / Q000201:enzymology* / Q000235:genetics; D013682:Teichoic Acids / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D011134:Polysaccharides; D011994:Recombinant Proteins; D013682:Teichoic Acids; C008984:polyribitol phosphate; D016695:Glycosyltransferases; D000117:Acetylglucosamine