Elaboration of neosamine rings in the biosynthesis of neomycin and butirosin

Chembiochem. 2007 Feb 12;8(3):283-8. doi: 10.1002/cbic.200600371.


The proteins Neo-11 and Neo-18 encoded in the neomycin gene cluster (neo) of Streptomyces fradiae NCIMB 8233 have been characterized as glucosaminyl-6'-oxidase and 6'-oxoglucosaminyl:L-glutamate aminotransferase, respectively. The joint activity of Neo-11 and Neo-18 is responsible for the conversion of paromamine to neamine in the biosynthetic pathway of neomycin through a mechanism of FAD-dependent dehydrogenation followed by a pyridoxal-5'-phosphate-mediated transamination. Neo-18 is also shown to catalyze deamination at C-6''' of neomycin, thus suggesting bifunctional roles of the two enzymes in the formation of both neosamine rings of neomycin. The product of the btrB gene, a homologue of neo-18 in the butirosin biosynthetic gene cluster (btr) in Bacillus circulans, exhibits the same activity as Neo-18; this indicates that there is a similar reaction sequence in both butirosin and neomycin biosynthesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / biosynthesis*
  • Bacillus / enzymology
  • Bacillus / genetics
  • Butirosin Sulfate / biosynthesis*
  • Carbohydrate Sequence
  • Cyclization
  • Glucosamine / analogs & derivatives*
  • Glucosamine / chemistry
  • Glucosamine / classification
  • Molecular Sequence Data
  • Multigene Family
  • Neomycin / biosynthesis*
  • Oxidoreductases / chemistry*
  • Oxidoreductases / genetics
  • Oxidoreductases / metabolism
  • Streptomyces / enzymology
  • Streptomyces / genetics
  • Transaminases / chemistry*
  • Transaminases / genetics
  • Transaminases / metabolism


  • Anti-Bacterial Agents
  • neosamine C
  • Butirosin Sulfate
  • Oxidoreductases
  • Transaminases
  • Neomycin
  • Glucosamine