西亚试剂：Mechanistic insights into a Ca2+-dependent family of α-mann

发布时间：2025-12-01

Mechanistic insights into a Ca2+-dependent family of α-mannosidases in a human gut symbiont

Yanping Zhu1,2,7, Michael D L Suits3,7, Andrew J Thompson3, Sambhaji Chavan4, Zoran Dinev5, Claire Dumon1,6, Nicola Smith1, Kelley W Moremen2, Yong Xiang2, Aloysius Siriwardena4, Spencer J Williams5, Harry J Gilbert1,2 & Gideon J Davies3

Colonic bacteria, exemplified by Bacteroides thetaiotaomicron, play a key role in maintaining human health by harnessing large families of glycoside hydrolases (GHs) to exploit dietary polysaccharides and host glycans as nutrients. Such GH family expansion is exemplified by the 23 family GH92 glycosidases encoded by the B. thetaiotaomicron genome. Here we show that these are α-mannosidases that act via a single displacement mechanism to utilize host N-glycans. The three-dimensional structure of two GH92 mannosidases defines a family of two-domain proteins in which the catalytic center is located at the domain interface, providing acid (glutamate) and base (aspartate) assistance to hydrolysis in a Ca2+-dependent manner. The three-dimensional structures of the GH92s in complex with inhibitors provide insight into the specificity, mechanism and conformational itinerary of catalysis. Ca2+ plays a key catalytic role in helping distort the mannoside away from its ground-state 4C1 chair conformation toward the transition state.

Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, UK.
Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, USA.
York Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York, UK.
Université de Picardie Jules Vernes, Faculté des Sciences, Laboratoire des Glucides, Centre National de la Recherche Scientifique-Unité Mixe de Recherche 6219, Amiens, France.
School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia.
Present address: INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, F-31400 Toulouse; Université de Toulouse; INSA, UPS, INP, LISBP, 135 Avenue de Rangueil, F-31077 Toulouse; CNRS, UMR5504, F-31400 Toulouse, France.
These authors contributed equally to this work.

• 以上资料由西亚试剂：http://www.xiyashiji.com/ 提供此产品的详细信息如密度,含量,分子式,分子量等均可在西亚官网查询   
• 相关产品如溴化汞硝酸亚汞氯化亚汞乙酸苯汞氯化钾汞 碘化汞钾硫氰酸汞硫酸亚汞氧化汞氯化汞碘化汞硝酸汞三氯氧磷三氯化磷碘甲烷二碘甲烷三碘甲烷三氟碘甲烷氘代碘甲烷碘乙烷1,2-二碘乙烷甲酸铷碘化铷溴化铷铬酸铷硫酸铷氟化铷硝酸铷氯化铷碳酸铷硫酸镱 碳酸镱氯化镱硝酸镱氧化镱等均有销售.欢迎订购

上一篇：立邦清远生产基地举行开工仪式
下一篇：西亚试剂：光敏色素蛋白如何告诉植物是白天还是夜晚