Biosynthesis of dTDP-6-deoxy-beta-D-allose, biochemical characterization of dTDP-4-keto-6-deoxyglucose reductase (GerKI) from Streptomyces sp. KCTC 0041BP

Glycobiology. 2007 Feb;17(2):119-26. doi: 10.1093/glycob/cwl060. Epub 2006 Oct 19.


dTDP-6-deoxy-d-allose, an unusual deoxysugar, has been identified as an intermediate in the mycinose biosynthetic pathway of several macrolide antibiotics. In order to characterize the biosynthesis of this deoxysugar, we have cloned and heterologously overexpressed gerK1 in Escherichia coli BL21 (DE3) cells. This gene encodes for a protein with the putative function of a dTDP-4-keto-6-deoxyglucose reductase, which appears to be involved in the dihydrochalcomycin (GERI-155) biosynthesis evidenced by Streptomyces sp KCTC 0041BP. Our results revealed that GerK1 exhibited a specific reductive effect on the 4-keto carbon of dTDP-4-keto-6-deoxy-d-allose, with the hydroxyl group in an axial configuration at the C3 position only. The enzyme catalyzed the conversion of dTDP-4-keto-6-deoxyglucose to dTDP-6-deoxy-beta-D-allose, according to the results of an in vitro coupled enzyme assay, in the presence of GerF (dTDP-4-keto-6-deoxyglucose 3-epimerase). The product was isolated, and its stereochemistry was determined via nuclear magnetic resonance analysis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Catalysis
  • Cloning, Molecular
  • Escherichia coli / genetics
  • Molecular Sequence Data
  • Nuclear Magnetic Resonance, Biomolecular
  • Nucleoside Diphosphate Sugars / biosynthesis*
  • Phylogeny
  • Sequence Analysis, DNA
  • Streptomyces / enzymology*
  • Sugar Alcohol Dehydrogenases / chemistry*
  • Sugar Alcohol Dehydrogenases / genetics
  • Sugar Alcohol Dehydrogenases / metabolism*
  • Thymine Nucleotides / biosynthesis*


  • Nucleoside Diphosphate Sugars
  • Thymine Nucleotides
  • deoxythymidine diphosphate-6-deoxyallose
  • Sugar Alcohol Dehydrogenases
  • thymidine diphosphate-4-keto-6-deoxy-D-glucose reductase

Associated data

  • GENBANK/AY118081