The gamma 1 and gamma 2 subunits of human liver alcohol dehydrogenase. cDNA structures, two amino acid replacements, and compatibility with changes in the enzymatic properties

Eur J Biochem. 1986 Sep 1;159(2):215-8. doi: 10.1111/j.1432-1033.1986.tb09855.x.

Abstract

cDNA clones corresponding to two alleles of the ADH3 locus were identified by hybridization with synthetic oligodeoxyribonucleotides specific for class I human liver alcohol dehydrogenase. Sequences were determined for a 1457-nucleotide cDNA, covering the whole gamma 2-coding region, and a 1224-nucleotide cDNA, including the region coding for amino acid residues 53-374 of the gamma 1 subunit. Two amino acid replacements between the gamma 1 and gamma 2 subunits were identified. At position 349, isoleucine in gamma 1 instead of valine in gamma 2 is a conservative exchange of a superficial residue which has been ascribed no special importance. The other exchange, at position 271, arginine in gamma 1 and glutamine in gamma 2, explains differences in enzyme properties. Electrophoretically, it is consistent with the less cathodic mobility of the gamma 2 subunit. Functionally, the location of the exchange at the surface of the coenzyme-binding pocket may influence the dissociation of the reduced coenzyme.

MeSH terms

  • Alcohol Dehydrogenase / analysis*
  • Alcohol Dehydrogenase / genetics
  • Amino Acid Sequence
  • Base Sequence
  • Coenzymes / analysis
  • DNA / analysis*
  • Humans
  • Liver / enzymology*

Substances

  • Coenzymes
  • DNA
  • Alcohol Dehydrogenase

Associated data

  • GENBANK/X04299
  • GENBANK/X04350