Dietary pectic glycans are degraded by coordinated enzyme pathways in human colonic Bacteroides.
Dietary pectic glycans are degraded by coordinated enzyme pathways in human colonic Bacteroides.
复制标题
饮食中的果糖聚糖会通过人类结肠菌属的协调酶途径降解。
DOI：
10.1038/s41564-017-0079-1
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发表时间：
2018-03
影响因子：
28.3
通讯作者：
Gilbert HJ
中科院分区：
文献类型：
--
作者：
Luis AS;Briggs J;Zhang X;Farnell B;Ndeh D;Labourel A;Baslé A;Cartmell A;Terrapon N;Stott K;Lowe EC;McLean R;Shearer K;Schückel J;Venditto I;Ralet MC;Henrissat B;Martens EC;Mosimann SC;Abbott DW;Gilbert HJ
人类结肠拟杆菌属物种可获得的主要营养物是聚糖，例如果胶，一种含有半乳糖醛酸（GalA）的共价连接的植物细胞壁多糖的网络。拟杆菌属的复杂碳水化合物代谢是由多糖利用位点或普尔斯协调的。在多形拟杆菌（Bacteroides thetaiotaomicron）（一种人类结肠细菌）中，已经鉴定了由不同果胶结构域激活的普尔斯，然而，这些位点促进这些含GalA的多糖降解的机制知之甚少。在这里，我们表明，每个PUL编排特定的果胶分子的代谢，从两个以前未知的糖苷水解酶（GH）家族招募酶。使鼠李糖半乳糖醛酸-I（RGI）的主链解聚的装置特别复杂。该系统含有几个GH，修剪连接到RGI的其他果胶结构域的残余物，而九种酶有助于降解的骨架，包括鼠李糖-GalA重复单元。果胶降解酶的催化性质被优化以保护激活特定普尔斯的聚糖线索，从而确保在整个生长过程中诱导分子的连续供应。拟杆菌属的贡献。果胶网络的代谢是由生物体之间的交叉喂养说明。
The major nutrients available to human colonic Bacteroides species are glycans exemplified by pectins, a network of covalently linked plant cell wall polysaccharides containing galacturonic acid (GalA). Metabolism of complex carbohydrates by the Bacteroides genus is orchestrated by polysaccharide utilisation loci or PULs. In Bacteroides thetaiotaomicron, a human colonic bacterium, the PULs activated by the different pectin domains have been identified, however, the mechanism by which these loci contribute to the degradation of these GalA-containing polysaccharides is poorly understood. Here we show that each PUL orchestrates the metabolism of specific pectin molecules, recruiting enzymes from two previously unknown glycoside hydrolase (GH) families. The apparatus that depolymerizes the backbone of rhamnogalacturonan-I (RGI) is particularly complex. This system contains several GHs that trim the remnants of other pectin domains attached to RGI, while nine enzymes contribute to the degradation of the backbone comprising a rhamnose-GalA repeating unit. The catalytic properties of the pectin degrading enzymes are optimized to protect the glycan cues that activate the specific PULs ensuring a continuous supply of inducing molecules throughout growth. The contribution of Bacteroides spp. to the metabolism of the pectic network is illustrated by cross-feeding between organisms.
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DOI：
10.1107/s090744491003982x
发表时间：
2011-04
期刊：
Acta crystallographica. Section D, Biological crystallography
影响因子：
--
作者：
Evans PR
通讯作者：
Evans PR
影响因子：
64.8
作者：
Glenwright AJ;Pothula KR;Bhamidimarri SP;Chorev DS;Baslé A;Firbank SJ;Zheng H;Robinson CV;Winterhalter M;Kleinekathöfer U;Bolam DN;van den Berg B
通讯作者：
van den Berg B
聚糖代谢如何塑造人类肠道微生物群。
DOI：
10.1038/nrmicro2746
发表时间：
2012-04-11
期刊：
Nature reviews. Microbiology
影响因子：
--
作者：
通讯作者：
--
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
影响因子：
11.2
作者：
Coenen, G. J.;Bakx, E. J.;Voragen, A. G. J.
通讯作者：
Voragen, A. G. J.