Alahuhta Markus, Luo Yonghua, Ding Shi You, Himmel Michael E, Lunin Vladimir V
BioSciences Center, National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401-3305, USA.
Acta Crystallogr Sect F Struct Biol Cryst Commun. 2011 May 1;67(Pt 5):527-30. doi: 10.1107/S1744309111003307. Epub 2011 Apr 20.
Here, a 2.0 Å resolution X-ray structure of Clostridium thermocellum cellulase K family 4 carbohydrate-binding module (CelK CBM4) is reported. The resulting structure was refined to an R factor of 0.212 and an R(free) of 0.274. Structural analysis shows that this new structure is very similar to the previously solved structure of C. thermocellum CbhA CBM4. Most importantly, these data support the previously proposed notion of an extended binding pocket using a novel tryptophan-containing loop that may be highly conserved in clostridial CBM4 proteins.
本文报道了嗜热栖热放线菌纤维素酶K家族4碳水化合物结合模块（CelK CBM4）的2.0 Å分辨率X射线结构。所得结构的R因子精修至0.212，自由R因子为0.274。结构分析表明，该新结构与先前解析的嗜热栖热放线菌CbhA CBM4结构非常相似。最重要的是，这些数据支持了先前提出的关于使用一个可能在梭菌CBM4蛋白中高度保守的含新型色氨酸环的扩展结合口袋的概念。
