Xanthomonas campestris pv. campestris gum Mutants: Effects on Xanthan Biosynthesis and Plant Virulence

• DOI: 10.1128/jb.180.7.1607-1617.1998
• Publication Date: 2019-12-31T16:31:29Z
• Authors: Federico Katzen; Diego U. Ferreiro; Cristian G. Oddo; M. Verónica Ielmini; Anke Becker; Alfred Pühler; Luis Ielpi
• Keywords: Xanthomonas; Gene cluster

ABSTRACT Xanthan is an industrially important exopolysaccharide produced by the phytopathogenic, gram-negative bacterium Xanthomonas campestris pv. campestris. It composed of polymerized pentasaccharide repeating units which are assembled sequential addition glucose-1-phosphate, glucose, mannose, glucuronic acid, and mannose on a polyprenol phosphate carrier (L. Ielpi, R. O. Couso, M. A. Dankert, J. Bacteriol. 175:2490–2500, 1993). A cluster 12 genes in region designated xpsI or gum has been suggested to encode proteins involved synthesis polymerization lipid intermediate. However, no experimental evidence supporting this suggestion published. In work, from biochemical analysis defined set X. mutants, we report data for assigning functions products genes. We also show that first step assembly lipid-linked intermediate severely affected combination certain non- mutations. addition, provide C-terminal domain gumD gene product sufficient its glucosyl-1-phosphate transferase activity. Finally, found alterations later stages xanthan biosynthesis reduce aggressiveness against plant.