Fig. 9

Multiple sequence alignment reveals structural diversity between clade I and II β-glucosidases. Three insertion regions, that are observed in Aspergillus aculeatus AaBGL1 (clade I), are not found in C. raphigera D2-BGL (clade II). The “prominent insertion region” observed in Aspergillus aculeatus AaBGL1 is absent from D2-BGL (from residues 597 to 603). The loop connecting TIM barrel and α/β sandwich domains are shorter in D2-BGL (from residues 307 to 318). D2-BGL has a shorter loop (from residues 166 to 168) than the corresponding loop in AaBGL1 at the entry region of the active site in the TIM barrel-like domain (from residues 200 to 215). In the multiple sequence alignment, amino acid residues involved in substrate binding and in catalysis reaction are in yellow and red, respectively. In the schema of the 3D structure of D2-BGL, TIM barrel-like domain, α/β sandwich domain and fibronectin III-like domain are represented by red, green and yellow segments, respectively. Gray segments represent sequences observed in AaBGL1. Green cylinder: α-helix; orange arrow: β-sheet