Glycosyl transferase GT2 genes mediate the biosynthesis of an unusual (1,3;1,4)-β-glucan exopolysaccharide in the bacterium Sarcina ventriculi.

Autor: Lampugnani ER; School of BioSciences, University of Melbourne, Parkville, Victoria, Australia.; Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, Tasmania, Australia., Ford K; School of BioSciences, University of Melbourne, Parkville, Victoria, Australia.; La Trobe Institute for Sustainable Agriculture and Food, La Trobe University, Bundoora, Victoria, Australia., Ho YY; School of BioSciences, University of Melbourne, Parkville, Victoria, Australia., van de Meene A; School of BioSciences, University of Melbourne, Parkville, Victoria, Australia.; Ian Holmes Imaging Centre, Bio21, The University of Melbourne, Parkville, Victoria, Australia., Lahnstein J; School of Agriculture, Food and Wine, University of Adelaide, Glen Osmond, South Australia, Australia., Tan HT; School of Agriculture, Food and Wine, University of Adelaide, Glen Osmond, South Australia, Australia., Burton RA; School of Agriculture, Food and Wine, University of Adelaide, Glen Osmond, South Australia, Australia., Fincher GB; School of Agriculture, Food and Wine, University of Adelaide, Glen Osmond, South Australia, Australia., Shafee T; La Trobe Institute for Sustainable Agriculture and Food, La Trobe University, Bundoora, Victoria, Australia., Bacic A; School of BioSciences, University of Melbourne, Parkville, Victoria, Australia.; La Trobe Institute for Sustainable Agriculture and Food, La Trobe University, Bundoora, Victoria, Australia., Zimmer J; Howard Hughes Medical Institute, University of Virginia School of Medicine, Charlottesville, Virginia, USA.; Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, Virginia, USA., Xing X; Division of Glycoscience, Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, Royal Institute of Technology (KTH), AlbaNova University Centre, Stockholm, Sweden., Bulone V; School of Agriculture, Food and Wine, University of Adelaide, Glen Osmond, South Australia, Australia.; Division of Glycoscience, Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, Royal Institute of Technology (KTH), AlbaNova University Centre, Stockholm, Sweden., Doblin MS; School of BioSciences, University of Melbourne, Parkville, Victoria, Australia.; La Trobe Institute for Sustainable Agriculture and Food, La Trobe University, Bundoora, Victoria, Australia., Roberts EM; Department of Biology, Rhode Island College, Providence, Rhode Island, USA.
Jazyk: angličtina
Zdroj: Molecular microbiology [Mol Microbiol] 2024 Jun; Vol. 121 (6), pp. 1245-1261. Date of Electronic Publication: 2024 May 15.
DOI: 10.1111/mmi.15276
Abstrakt: Linear, unbranched (1,3;1,4)-β-glucans (mixed-linkage glucans or MLGs) are commonly found in the cell walls of grasses, but have also been detected in basal land plants, algae, fungi and bacteria. Here we show that two family GT2 glycosyltransferases from the Gram-positive bacterium Sarcina ventriculi are capable of synthesizing MLGs. Immunotransmission electron microscopy demonstrates that MLG is secreted as an exopolysaccharide, where it may play a role in organizing individual cells into packets that are characteristic of Sarcina species. Heterologous expression of these two genes shows that they are capable of producing MLGs in planta, including an MLG that is chemically identical to the MLG secreted from S. ventriculi cells but which has regularly spaced (1,3)-β-linkages in a structure not reported previously for MLGs. The tandemly arranged, paralogous pair of genes are designated SvBmlgs1 and SvBmlgs2. The data indicate that MLG synthases have evolved different enzymic mechanisms for the incorporation of (1,3)-β- and (1,4)-β-glucosyl residues into a single polysaccharide chain. Amino acid variants associated with the evolutionary switch from (1,4)-β-glucan (cellulose) to MLG synthesis have been identified in the active site regions of the enzymes. The presence of MLG synthesis in bacteria could prove valuable for large-scale production of MLG for medical, food and beverage applications.
(© 2024 John Wiley & Sons Ltd.)
Databáze: MEDLINE
Externí odkaz: