Jörnvall H
Eur J Biochem. 1977 Feb;72(3):443-52. doi: 10.1111/j.1432-1033.1977.tb11268.x.
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.
酵母和马肝醇脱氢酶一级结构的比较表明，这两种酶是同源的，但亲缘关系较远。共同区域之间的总体位置一致性为25%，两种酶中均存在一些缺失/插入，最长的明显对应21个残基，这表明不同亚基大小在很大程度上是由内部差异造成的。结构相似性的变化可能与功能需求相关，但与马蛋白先前已知三级结构中的整个结构域没有直接关联。这两种酶最相似的区域影响活性位点片段，而最不相似的两个区域似乎影响一个功能未知的环结构以及一个参与亚基相互作用的片段。这些差异可能与锌结合特性和四级结构的变化相关。与内部链长差异较大相对应的额外区域在序列上与马酶的后续片段明显一致，并且还注意到了内部一致性的其他元素，或与其他脱氢酶的表面相似性。这些特征与随机分布并不能完全区分开来，但鉴于醇脱氢酶在物种间存在广泛差异，一些进化方面的考量不能被排除，在这种情况下，一个将这些酶以及相关酶的所有区域与共同祖先联系起来的模型被证明与所有已知观察结果相符。
