부산대학교 도서관

The solution structure of a synthetic 38-residue cellulose-binding domain (CBD) of endoglucanase I from Trichoderma reesei (CBDEGI) was determined by two-dimensional 1H-NMR spectroscopy. 100 structures were generated from a total of 599 NOE derived distance restraints and 28 φ and 14 χ dihedral angle restraints. For the final set of 19 selected structures, the rms deviation about the mean structure was 0.83 ± 0.26 Å for all atoms and 0.50 ± 0.22 Å for the backbone atoms. The structure of CBDEGI was very similar to that of CBD of cellobiohydrolase I from T. reesei (CBDCBHI). The backbone trace of CBDEGI followed closely the irregular triple-stranded antiparallel β-sheet structure of CBDCBHI. Moreover, apart from the different side chains of Trp7 (CBDEGI) and Tyr5 (CBDCBHI), the cellulose-binding face of CBDEGI was similar to that of CBDCBHI within the precision of the structures. Finally, the interaction between CBDEGI and soluble sugars was investigated using cellopentaose and cellohexaose as substrates. Experiments showed that the interactions between CBDEGI and cellobiose units of sugars are specific, supporting the previously presented model for the CBD binding to crystalline cellulose. [ABSTRACT FROM AUTHOR]