title: Chemometric Analysis of Bacterial Peptidoglycan Reveals Atypical Modifications That Empower the Cell Wall against Predatory Enzymes and Fly Innate Immunity.
abstract: Peptidoglycan is a fundamental structure for most bacteria. It contributes to the cell morphology and provides cell wall integrity against environmental insults. While several studies have reported a significant degree of variability in the chemical composition and organization of peptidoglycan in the domain Bacteria, the real diversity of this polymer is far from fully explored. This work exploits rapid ultraperformance liquid chromatography and multivariate data analysis to uncover peptidoglycan chemical diversity in the Class Alphaproteobacteria, a group of Gram negative bacteria that are highly heterogeneous in terms of metabolism, morphology and life-styles. Indeed, chemometric analyses revealed novel peptidoglycan structures conserved in Acetobacteria: amidation at the α-(l)-carboxyl of meso-diaminopimelic acid and the presence of muropeptides cross-linked by (1-3) l-Ala-d-(meso)-diaminopimelate cross-links. Both structures are growth-controlled modifications that influence sensitivity to Type VI secretion system peptidoglycan endopeptidases and recognition by the Drosophila innate immune system, suggesting relevant roles in the environmental adaptability of these bacteria. Collectively our findings demonstrate the discriminative power of chemometric tools on large cell wall-chromatographic data sets to discover novel peptidoglycan structural properties in bacteria.
authors.affiliation: Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå Centre for Microbial Research, Umeå University , 90187 Umeå, Sweden.
authors.forename: Akbar
authors.initials: A
authors.lastname: Espaillat
authors.affiliation: Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå Centre for Microbial Research, Umeå University , 90187 Umeå, Sweden.
authors.forename: Oskar
authors.initials: O
authors.lastname: Forsmo
authors.affiliation: Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas , Ramiro de Maeztu 9, 28040 Madrid, Spain.
authors.forename: Khouzaima
authors.initials: K
authors.lastname: El Biari
authors.affiliation: Department of Chemistry, Umeå University , 90187 Umeå, Sweden.
authors.forename: Rafael
authors.initials: R
authors.lastname: Björk
authors.affiliation: Global Health Institute, Swiss Federal Institute of Technology , Station 19, CH-1015 Lausanne, Switzerland.
authors.forename: Bruno
authors.initials: B
authors.lastname: Lemaitre
authors.affiliation: Department of Chemistry, Umeå University , 90187 Umeå, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Trygg
authors.affiliation: Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas , Ramiro de Maeztu 9, 28040 Madrid, Spain.
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Cañada
authors.affiliation: Centro de Biología Molecular "Severo Ochoa", Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas , Madrid 28049, Spain.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: de Pedro
authors.affiliation: Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå Centre for Microbial Research, Umeå University , 90187 Umeå, Sweden.
authors.forename: Felipe
authors.initials: F
authors.lastname: Cava
mesh_terms: D020561:Alphaproteobacteria / Q000737:chemistry / Q000166:cytology; D000818:Animals; D002473:Cell Wall / Q000378:metabolism*; D019295:Computational Biology; D004331:Drosophila melanogaster / Q000187:drug effects / Q000276:immunology*; D010450:Endopeptidases / Q000378:metabolism; D007113:Immunity, Innate / Q000187:drug effects*; D010457:Peptidoglycan / Q000378:metabolism* / Q000494:pharmacology*
chemical_list: D010457:Peptidoglycan; D010450:Endopeptidases