Uronic polysaccharide degrading enzymes
Uronic polysaccharide degrading enzymes
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DOI：
10.1016/j.sbi.2014.07.012
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发表时间：
2014-10-01
影响因子：
6.8
通讯作者：
Cygler, Miroslaw
中科院分区：
文献类型：
--
作者：
Garron, Marie-Line;Cygler, Miroslaw
在过去的几年中，多糖裂解酶（PL）的结构和功能领域取得了进展。分类的多糖裂解酶家族数量已增加至 23 个，更详细的分析可以识别更密切相关的亚家族，从而使每个亚家族与独特底物之间的相关性更强。尚未分类的多糖裂解酶的数量也有所增加，我们预计测序项目将允许许多这些未分类的序列作为新的家族出现。 PL 结构分析的进展使得每个家族和两种未分类的酶至少有一个代表性结构。新确定的结构具有先前在其他 PL 家族中观察到的折叠，其催化机制遵循其他 PL 酶的金属辅助或 Tyr/His 机制特征。 PL 与糖苷水解酶 (GH) 的比较表明，两个类别都有一些共同的折叠，但只有 β 螺旋折叠才强烈表明来自共同祖先的不同进化。对细菌基因组的分析发现了含有多种多糖裂解酶、多糖利用位点 (PUL) 的基因簇，以及它们的基因互补体表明它们被组织起来完全加工特定的多糖。
In the past several years progress has been made in the field of structure and function of polysaccharide lyases (PLs). The number of classified polysaccharide lyase families has increased to 23 and more detailed analysis has allowed the identification of more closely related subfamilies, leading to stronger correlation between each subfamily and a unique substrate. The number of as yet unclassified polysaccharide lyases has also increased and we expect that sequencing projects will allow many of these unclassified sequences to emerge as new families. The progress in structural analysis of PLs has led to having at least one representative structure for each of the families and for two unclassified enzymes. The newly determined structures have folds observed previously in other PL families and their catalytic mechanisms follow either metal-assisted or Tyr/His mechanisms characteristic for other PL enzymes. Comparison of PLs with glycoside hydrolases (GHs) shows several folds common to both classes but only for the beta-helix fold is there strong indication of divergent evolution from a common ancestor. Analysis of bacterial genomes identified gene clusters containing multiple polysaccharide cleaving enzymes, the Polysaccharides Utilization Loci (PULs), and their gene complement suggests that they are organized to process completely a specific polysaccharide.