Pseudoglycosyltransferase catalyzes nonglycosidic C-N coupling in validamycin a biosynthesis

J Am Chem Soc. 2011 Aug 10;133(31):12124-35. doi: 10.1021/ja203574u. Epub 2011 Jul 18.


Glycosyltransferases are ubiquitous in nature. They catalyze a glycosidic bond formation between sugar donors and sugar or nonsugar acceptors to produce oligo/polysaccharides, glycoproteins, glycolipids, glycosylated natural products, and other sugar-containing entities. However, a trehalose 6-phosphate synthase-like protein has been found to catalyze an unprecedented nonglycosidic C-N bond formation in the biosynthesis of the aminocyclitol antibiotic validamycin A. This dedicated 'pseudoglycosyltransferase' catalyzes a condensation between GDP-valienol and validamine 7-phosphate to give validoxylamine A 7'-phosphate with net retention of the 'anomeric' configuration of the donor cyclitol in the product. The enzyme operates in sequence with a phosphatase, which dephosphorylates validoxylamine A 7'-phosphate to validoxylamine A.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biocatalysis
  • Glucosyltransferases / chemistry
  • Glucosyltransferases / metabolism*
  • Inositol / analogs & derivatives
  • Inositol / biosynthesis
  • Inositol / chemistry
  • Molecular Conformation
  • Stereoisomerism


  • Inositol
  • validamycins
  • Glucosyltransferases