Crystal structure of endo-beta-N-acetylglucosaminidase H at 1.9 A resolution: active-site geometry and substrate recognition.
Crystal structure of endo-beta-N-acetylglucosaminidase H at 1.9 A resolution: active-site geometry and substrate recognition.
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分辨率为 1.9 A 的内切-β-N-乙酰氨基葡萄糖苷酶 H 的晶体结构：活性位点几何结构和底物识别。
DOI：
10.1016/s0969-2126(01)00178-2
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
VanRoey,P
中科院分区：
文献类型：
--
作者：
Rao,V;Guan,C;VanRoey,P
背景：内切-β-N-乙酰氨基葡萄糖苷酶H（Endo H）是褶纹链霉菌分泌的一种内切糖苷酶，可水解天冬酰胺连接的高甘露糖寡糖的核心N-乙酰氨基葡萄糖残基之间的糖苷键。Endo H是糖生物学研究中常用的试剂，包括糖蛋白中寡糖的表征。正在进行的晶体学研究的Endo H和相关的endoglycosidases的目的是确定这些enzymes.ResultsThe的不同底物特异性的分子特征，Endo H的三维结构已被确定为1.9 μ m分辨率。该酶的总体折叠是包含8个β-链/环/α-螺旋单元的不规则（α/β）8-桶。单元5和单元6在分子的顶部具有非常短的环部分，并且它们的α-螺旋被扩展几何形状的部分取代。单元2的环包括小的双链反平行β-折叠。一个浅的弯曲裂缝从单元5和6的区域穿过分子表面，越过β-桶的核心，到达环2的β-折叠区域。该裂缝在β-桶的核心上方含有推定的催化残基Asp 130和Glu 132。这些残基被几个芳族残基包围。结论Endo H与Endo F1的结构非常相似，Endo H和Endo F1的结构比较支持了先前提出的底物结合和识别模型，其中环2的面积决定底物特异性，并且单元5和6的α-螺旋缺失以容纳底物的蛋白质部分。
Background:Endo-β-N-acetylglucosaminidase H (Endo H), an endoglycosidase secreted byStreptomyces plicatus,hydrolyzes the glycosidic bond between the coreN-acetylglucosamine residues of asparagine-linked high-mannose oligosaccharides. Endo H is a commonly used reagent in glycobiology research, including the characterization of oligosaccharides in glycoproteins. On-going crystallographic studies of Endo H and related endoglycosidases are aimed at identifying the molecular features that determine the different substrate specificities of these enzymes.ResultsThe three-dimensional structure of Endo H has been determined to 1.9 å resolution. The overall fold of the enzyme is that of an irregular (α/β)8-barrel comprising eightβ-strand/loop/α-helix units. Units 5 and 6 have very short loop sections at the top of the molecule and theirα-helices are replaced by sections of extended geometry. The loop of unit 2 includes a small two-stranded antiparallelβ-sheet. A shallow curved cleft runs across the surface of the molecule from the area of units 5 and 6, over the core of theβ-barrel to the area of theβ-sheet of loop 2. This cleft contains the putative catalytic residues Asp130 and Glu132 above the core of theβ-barrel. These residues are surrounded by several aromatic residues. The loop 2 area of the cleft is formed by neutral polar residues, mostly asparagines.ConclusionThe structure of Endo H is very similar to that of Endo F1, a closely related endoglycosidase secreted byFlavobacterium meningosepticum.Detailed comparison of the structures of Endo H and Endo F1supports the model previously proposed for substrate binding and recognition, in which the area of loop 2 determines the substrate specificity and theα-helices of units 5 and 6 are missing to accommodate the protein moiety of the substrate.
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DOI：
10.1016/s0021-9258(18)55057-2
发表时间：
1991-10
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
M. Kuranda;P. Robbins
通讯作者：
M. Kuranda;P. Robbins
影响因子：
--
作者：
B. C. Wang
通讯作者：
B. C. Wang
两种内切-β-N-乙酰氨基葡萄糖苷酶（endo H 和 end F1）的结晶和初步晶体学分析。
影响因子：
5.6
作者：
VanRoey,P;Silva,GH;Rao,V;PlummerJr,TH;Tarentino,AL;Guan,C
通讯作者：
Guan,C
DOI：
10.1016/s0021-9258(18)52343-7
发表时间：
1991-01
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Robert B. TrimbleS;A. Tarentino
通讯作者：
Robert B. TrimbleS;A. Tarentino
鉴定褶皱链霉菌内切 β-N-乙酰氨基葡萄糖苷酶 H 活性所必需的两种天冬氨酸和一种谷氨酸。
影响因子：
3.9
作者：
B. Schmidt;E. Ashizawa;A. Jarnagin;S. Lynn;G. Noto;L. Woodhouse;D. Estell;P. Lad
通讯作者：
P. Lad