The NodC protein of Azorhizobium caulinodans is an N-acetylglucosaminyltransferase.
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.
Geremia
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RA
Laboratorium voor Genetica, Universiteit Gent, Belgium.
Mergaert
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P
Geelen
D
D
Van Montagu
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M
Holsters
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D001419:Bacteria / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002240:Carbohydrate Sequence; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D008969:Molecular Sequence Data; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics / Q000378:metabolism*; D009844:Oligosaccharides / Q000096:biosynthesis*
D001426:Bacterial Proteins; D009844:Oligosaccharides; D017351:N-Acetylglucosaminyltransferases; C060771:NodC protein, Rhizobiales; C037649:N-acetyllactosaminide beta-1,6-N-acetylglucosaminyltransferase