Differences between Alcohol Dehydeogenases

Abstract

Comparisons of the primary structures of yeast and horse liver alcohol dehydrogenases reveal that the enzymes are homologous but distantly related. The overall positional identity is 25 between common regions, and several deletions/insertions occur in either enzyme, the longest apparently corresponding to 21 residues, showing that the different subunit sizes are largely explained by internal differences.Variabilities in the structural similarities can be coupled with functional requirements but not directly with whole domains in the previously known tertiary structure of the horse protein. The two most similar regions of the enzymes affect active-site segments and the two most dissimilar regions seem to affect a loop structure without known function, and a segment participating in subunit interactions. The dissimilarities may probably be correlated with changes in zinc-binding properties and quaternary structures.The extra region corresponding to the large internal chain-length difference shows an apparent coincidence in sequence to a following segment of the horse enzyme, and additional elements of internal coincidences, or superficial similarities with other dehydrogenases, are noticed. These characteristics are not fully distinguishable from chance distributions but in view of the extensive species variations in alcohol dehydrogenases some evolutionary considerations may not be excluded, in which case a model relating all regions of these and associated enzymes to a common ancestor is shown to be compatible with all known observations.

Extensive variations and basic features in the alcohol dehydrogenase – sorbitol dehydrogenase family

“…In the case ofyeast alcohol dehydrogenase, two isozyme variants have been analyzed in Saccharomyces cerevisiae [I 3 -151, as well as enzymes from different strains [I31 and functional mutants [I61 of this species. The structure of Schizosaccharomyces pombe alcohol dehydrogenase has also been deduced [17] but, for the sake of clarity, the enzyme structure used in the present study is that of the cytoplasmic, constitutive isozyme of Saccharomyces cerevisiae, with positional alternatives from [6] where differences in the reports [6, 141 appear to be compatible with strain variations. This is the most widely studied yeast alcohol dehydrogenase [7,18].…”

“…The primary structure of sheep liver sorbitol dehydrogenase [I] and yeast and horse liver alcohol dehydrogenases [6] were compared in moving frames using spans of 15 -30 residues to cover all possible combinations [3]. Gaps were not considered in individual matches within the span size but were allowed for by relating shifts between adjacent matches in all answers from the moving frame.…”

“…The alcohol dehydrogenases show considerable divergence in primary structure, quaternary structure, isozyme development, substrate specificity and other functional characteristics [6-91, so detailed comparisons covering the entire structure of sorbitol dehydrogenase are necessary. Of particular interest are functionally important residues and adjacent regions, structures concerned with substrate specificities, positions of insertions or deletions, and altered surface properties that could explain the different quaternary structures.In the present work, overall similarities and differences between these dehydrogenases are determined and related to the differences within the alcohol dehydrogenases [6,7], to the Enzymes. Horse liver alcohol dehydrogenase (EC 1.1.1.1); yeast alcohol dehydrogenase (EC 1.1.1 .l); sorbitol dehydrogenase (EC 1.1.1.14); lactate dehydrogenase (EC 1.1.1.27).…”

“…In the present work, overall similarities and differences between these dehydrogenases are determined and related to the differences within the alcohol dehydrogenases [6,7], to the Enzymes. Horse liver alcohol dehydrogenase (EC 1.1.1.1); yeast alcohol dehydrogenase (EC 1.1.1 .l); sorbitol dehydrogenase (EC 1.1.1.14); lactate dehydrogenase (EC 1.1.1.27).…”

In silico analysis of heme oxygenase structural homologues identifies group‐specific conservations

“…This residue is found in the turn between α‐1 and α‐2 30. Conserved glycines are often found in turns in enzyme structures or at positions where a side chain would lead to steric conflicts in many enzyme families 31, 32, 33, 34. Phe47{173} is 71% conserved overall and is found in RNR1As, most thiaminases, and HOs except plant species.…”