Department of Biotechnology, The University of Tokyo, Tokyo, Japan.
FEBS Lett. 2010 Mar 19;584(6):1205-11. doi: 10.1016/j.febslet.2010.02.027. Epub 2010 Feb 14.
The crystal structures of a carbohydrate-binding module (CBM) family 28 domain of endoglucanase Cel5A from Clostridium josui have been determined in ligand-free and complex forms with cellobiose, cellotetraose, and cellopentaose as the first complex structures of this family. In the cleft of a beta-sandwich fold, the ligands are recognized by stacking interactions and hydrogen bonds. Conformations of the bound cellooligosaccharides are similar to those in crystals and solution but clearly different from the cellulose structure. Interestingly, the glucan chain bound on CBM28 is in the opposite direction of that bound to CBM17, although these families share significant structural similarity.
已解析出内切葡聚糖酶 Cel5A 的碳水化合物结合模块（CBM）家族 28 结构域的晶体结构，其中包含与纤维二糖、纤维四糖和纤维五糖的无配体和复合物形式，这是该家族的首个复合物结构。在β-三明治折叠的裂缝中，通过堆积相互作用和氢键来识别配体。结合的低聚纤维素的构象与晶体和溶液中的相似，但明显不同于纤维素结构。有趣的是，尽管这些家族具有显著的结构相似性，但结合在 CBM28 上的葡聚糖链的方向与结合在 CBM17 上的葡聚糖链相反。
