Chitinases, chitosanases, and lysozymes can be divided into procaryotic and eucaryotic families sharing a conserved core
Chitinases, chitosanases, and lysozymes can be divided into procaryotic and eucaryotic families sharing a conserved core
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DOI：
10.1038/nsb0296-133
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发表时间：
1996-02-01
期刊：
影响因子：
--
通讯作者：
Robertus, JD
中科院分区：
文献类型：
--
作者：
Monzingo, AF;Marcotte, EM;Robertus, JD
大麦几丁质酶、细菌壳聚糖酶、鹅源溶菌酶（GEWL）、噬菌体溶菌酶（T4 L）和鸡源溶菌酶（HEWL）都能水解相关多糖。这些蛋白质没有显著的氨基酸相似性，但具有结构不变的核心，由两个螺旋和一个三链β-折叠组成，形成底物结合和催化裂缝。这些酶代表了水解酶的一个超家族，它们可能是通过分化进化而产生的。基于结构标准，我们将水解酶超家族分为细菌家族（壳聚糖酶和T4 L）和以壳聚糖酶和GEWL为代表的真核家族。两个家族都含有核心，但具有不同的N-和C-末端结构域。几丁质酶和壳聚糖酶在超家族中的列入表明该组的原型催化机制是一种转化机制。HEWL的固位机制是不寻常的。
Barley chitinase, bacterial chitosanase, and lysozymes from goose (GEWL), phage (T4L) and hen (HEWL) all hydrolyse related polysaccharides. The proteins share no significant aminoacid similarities, but have a structurally invariant core consisting of two helices and a three-stranded beta-sheet which form the substrate-binding and catalytic cleft. These enzymes rep resent a superfamily of hydrolases which are likely to have arisen by divergent evolution. Based on structural criteria, we divide the hydrolase superfamily into a bacterial family (chitosanase and T4L) and a eucaryotic family represented by chitinase and GEWL. Both families contain the core but have differing N- and C-terminal domains. Inclusion of chitinase and chitosanase in the superfamily suggests the archetypal catalytic mechanism of the group is an inverting mechanism. The retaining mechanism of HEWL is unusual.