Höög J O, Hedén L O, Larsson K, Jörnvall H, von Bahr-Lindström H
Eur J Biochem. 1986 Sep 1;159(2):215-8. doi: 10.1111/j.1432-1033.1986.tb09855.x.
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.
通过与针对I类人肝脏乙醇脱氢酶的合成寡脱氧核糖核苷酸杂交，鉴定出与ADH3基因座的两个等位基因相对应的cDNA克隆。测定了一个1457个核苷酸的cDNA序列，其覆盖整个γ2编码区，以及一个1224个核苷酸的cDNA序列，包括编码γ1亚基氨基酸残基53 - 374的区域。鉴定出γ1和γ2亚基之间的两个氨基酸替换。在第349位，γ1中的异亮氨酸而非γ2中的缬氨酸是一个表面残基的保守交换，该残基未被赋予特殊重要性。另一个交换在第271位，γ1中的精氨酸和γ2中的谷氨酰胺，解释了酶性质的差异。在电泳方面，这与γ2亚基较低的阴极迁移率一致。在功能上，交换位于辅酶结合口袋表面的位置可能会影响还原辅酶的解离。
