Structure of a bifunctional alcohol dehydrogenase involved in bioethanol generation in Geobacillus thermoglucosidasius

Acta Crystallogr D Biol Crystallogr. 2013 Oct;69(Pt 10):2104-15. doi: 10.1107/S0907444913020349. Epub 2013 Sep 20.


Bifunctional alcohol/aldehyde dehydrogenase (ADHE) enzymes are found within many fermentative microorganisms. They catalyse the conversion of an acyl-coenzyme A to an alcohol via an aldehyde intermediate; this is coupled to the oxidation of two NADH molecules to maintain the NAD(+) pool during fermentative metabolism. The structure of the alcohol dehydrogenase (ADH) domain of an ADHE protein from the ethanol-producing thermophile Geobacillus thermoglucosidasius has been determined to 2.5 Å resolution. This is the first structure to be reported for such a domain. In silico modelling has been carried out to generate a homology model of the aldehyde dehydrogenase domain, and this was subsequently docked with the ADH-domain structure to model the structure of the complete ADHE protein. This model suggests, for the first time, a structural mechanism for the formation of the large multimeric assemblies or `spirosomes' that are observed for this ADHE protein and which have previously been reported for ADHEs from other organisms.

Keywords: ADH domain; ADHE; Geobacillus thermoglucosidasius; bioethanol.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alcohol Dehydrogenase / chemistry*
  • Alcohol Dehydrogenase / genetics
  • Alcohol Dehydrogenase / isolation & purification
  • Amino Acid Sequence
  • Biofuels / microbiology*
  • Crystallography, X-Ray
  • Ethanol*
  • Fermentation
  • Geobacillus / enzymology*
  • Geobacillus / genetics
  • Geobacillus / growth & development
  • Models, Molecular*
  • Molecular Sequence Data
  • Multienzyme Complexes / chemistry
  • Multienzyme Complexes / genetics


  • Biofuels
  • Multienzyme Complexes
  • Ethanol
  • Alcohol Dehydrogenase

Associated data

  • PDB/3ZDR