Structural and sequence comparisons of quinone oxidoreductase, zeta-crystallin, and glucose and alcohol dehydrogenases
Structural and sequence comparisons of quinone oxidoreductase, zeta-crystallin, and glucose and alcohol dehydrogenases
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DOI：
10.1006/abbi.1996.0158
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发表时间：
1996-04-01
影响因子：
3.9
通讯作者：
Ollis, DL
中科院分区：
文献类型：
--
作者：
Edwards, KJ;Barton, JD;Ollis, DL
醌氧化还原酶、xi-结晶蛋白、葡萄糖脱氢酶和乙醇脱氢酶属于中链脱氢酶/还原酶超家族。大肠杆菌醌氧化还原酶（QOR）和热原体嗜酸葡萄糖脱氢酶的晶体结构最近被确定，并与众所周知的马肝酒精脱氢酶的结构进行了比较。基于结构的比较证实了这三种酶具有广泛的整体结构同源性，尽管序列同一性较低，但最显著的区别是在QOR中缺乏催化和结构锌离子。具有醌氧化还原酶活性且与大肠杆菌醌氧化还原酶序列高度同源的眼球晶状体结构蛋白。对催化作用重要的残基已经改变，酶的功能和活性已经分化，说明了酶超家族之间分化进化的经典例子，(C) 1996学术出版社，Inc.。
Quinone oxidoreductase, xi-crystallin, glucose dehydrogenase, and alcohol dehydrogenase belong to a superfamily of medium-chain dehydrogenase/reductases, The crystal structures of Escherichia coli quinone oxidoreductase (QOR) and Thermoplasma acidophilun glucose dehydrogenase have recently been determined and are compared here with the well-known structure of horse liver alcohol dehydrogenase. A structurally based comparison of these three enzymes confirms that they possess extensive overall structural homology despite low sequence identity, The most significant difference is the absence of the catalytic and structural zinc ions in QOR, A multiple structure-based sequence alignment has been constructed for the three enzymes and extended to include xi-crystallin, an eye lens structural protein with quinone oxidereductase activity and high sequence identity to E. coli quinone oxidoreductase. Residues which are important for catalysis have been altered and the functions and activities of the enzymes have diverged, illustrating a classic example of divergent evolution among a superfamily of enzymes, (C) 1996 Academic Press, Inc.