Characterization of a novel class of glyoxylate reductase belonging to the β-hydroxyacid dehydrogenase family in Acetobacter aceti

Biosci Biotechnol Biochem. 2020 Nov;84(11):2303-2310. doi: 10.1080/09168451.2020.1797470. Epub 2020 Jul 30.


Enzymes related to β-hydroxyacid dehydrogenases/3-hydroxyisobutyrate dehydrogenases are ubiquitous, but most of them have not been characterized. An uncharacterized protein with moderate sequence similarities to Gluconobacter oxydans succinic semialdehyde reductase and plant glyoxylate reductases/succinic semialdehyde reductases was found in the genome of Acetobacter aceti JCM20276. The corresponding gene was cloned and expressed in Escherichia coli. The gene product was purified and identified as a glyoxylate reductase that exclusively catalyzed the NAD(P)H-dependent reduction of glyoxylate to glycolate. The strict substrate specificity of this enzyme to glyoxylate, the diverged sequence motifs for its binding sites with cofactors and substrates, and its phylogenetic relationship to homologous enzymes suggested that this enzyme represents a novel class of enzymes in the β-hydroxyacid dehydrogenase family. This study may provide an important clue to clarify the metabolism of glyoxylate in bacteria. Abbreviations: GR: glyoxylate reductase; GRHPR: glyoxylate reductase/hydroxypyruvate reductase; HIBADH: 3-hydroxyisobutyrate dehydrogenase; SSA: succinic semialdehyde; SSAR: succinic semialdehyde reductase.

Keywords: 3-hydroxyisobutyrate dehydrogenase; Glyoxylate reductase; NAD(P)H; acetic acid bacteria; β-hydroxyacid dehydrogenase.

MeSH terms

  • Acetobacter / enzymology*
  • Alcohol Oxidoreductases / chemistry
  • Alcohol Oxidoreductases / metabolism*
  • Amino Acid Sequence
  • Hydrogen-Ion Concentration
  • Kinetics
  • Metals / pharmacology
  • Phylogeny
  • Substrate Specificity


  • Metals
  • Alcohol Oxidoreductases
  • glyoxylate reductase

Supplementary concepts

  • Acetobacter aceti