Open AccessThe NodC protein of Azorhizobium caulinodans is an N-acetylglucosaminyltransferase.
Author(s) -
R. Geremia,
Peter Mergaert,
Danny Geelen,
Marc Van Montagu,
Marcelle Holsters
Publication year - 1994
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.91.7.2669
Subject(s) - nod factor , nod , biochemistry , bradyrhizobium japonicum , biosynthesis , mutant , biology , microbiology and biotechnology , escherichia coli , oligosaccharide , bradyrhizobium , bacteria , gene , rhizobium , symbiosis , rhizobiaceae , rhizobia , genetics
Nod factors are signal molecules produced by Azorhizobium, Bradyrhizobium, and Rhizobium species that trigger nodule formation in leguminous host plants. The backbone of Nod factors consists of a beta-1,4-N-acetylglucosamine oligosaccharide from which the N-acetyl group at the nonreducing end is replaced by a fatty acid. The nodABC gene products are necessary for backbone biosynthesis. By incubation of cell extracts from Azorhizobium caulinodans with radioactive uridine diphosphate-N-acetylglucosamine, Nod factor precursors were identified and characterized as beta-1,4-N-acetylglucosamine oligosaccharides. By analysis of different nod gene mutants and by expression of nodC in Escherichia coli, the N-acetylglucosaminyltransferase activity was ascribed to the NodC protein. The results suggest that the first step in biosynthesis of Nod factors is the assembly of the oligosaccharide chain.