Din N, Forsythe I J, Burtnick L D, Gilkes N R, Miller R C, Warren R A, Kilburn D G
Department of Microbiology, University of British Columbia, Vancouver, Canada.
Mol Microbiol. 1994 Feb;11(4):747-55. doi: 10.1111/j.1365-2958.1994.tb00352.x.
Cellulomonas fimi endo-beta-1,4-glucanase A (CenA) contains a discrete N-terminal cellulose-binding domain (CBDCenA). Related CBDs occur in at least 16 bacterial glycanases and are characterized by four highly conserved Trp residues, two of which correspond to W14 and W68 of CBDCenA. The adsorption of CBDCenA to crystalline cellulose was compared with that of two Trp mutants (W14A and W68A). The affinities of the mutant CBDs for cellulose were reduced by approximately 50- and 30-fold, respectively, relative to the wild type. Physical measurements indicated that the mutant CBDs fold normally. Fluorescence data indicated that W14 and W68 were exposed on the CBD, consistent with their participation in binding to cellobiosyl residues on the cellulose surface.
纤维单胞菌内切-β-1,4-葡聚糖酶A（CenA）含有一个独立的N端纤维素结合结构域（CBDCenA）。相关的CBD存在于至少16种细菌聚糖酶中，其特征是有四个高度保守的色氨酸残基，其中两个对应于CBDCenA的W14和W68。将CBDCenA与两种色氨酸突变体（W14A和W68A）对结晶纤维素的吸附进行了比较。相对于野生型，突变体CBD对纤维素的亲和力分别降低了约50倍和30倍。物理测量表明突变体CBD能正常折叠。荧光数据表明W14和W68暴露在CBD上，这与它们参与结合纤维素表面的纤维二糖残基一致。
