Schematic representation of the recombinant proteins used in this study. The modular notation, structure and molecular mass of each protein are indicated. Red, yellow and light blue indicate C. thermocellum-derived cohesin/dockerin, carbohydrate binding module (CBM) and enzyme-related components, respectively. Dark blue indicates A. cellulolyticus-derived cohesin/dockerin modules, and green indicates B. cellulosolvens-derived modules. (a) The basic chimaeric scaffoldin containing three divergent cohesins: the third cohesin of scaffoldin ScaC from A. cellulolyticus (A), the third cohesin of ScaB from B. cellulosolvens (B), the second cohesin of the CipA scaffoldin from C. thermocellum (T) plus a CBM3a module of the same scaffoldin (c). See Additional file 1: Table S1 for the molecular weights of the respective chimaeric scaffoldins. (b) The length of each module and its C-flanking linkers in amino acid residues. (c) Recombinant cellulases used in this study. In the modular notation of the enzymes, the number indicates the GH family of the catalytic domain. S, K and A indicate the original name of the enzyme (Cel48S, Cel9K and Cel8A, respectively). The chimaeric Cel9K includes a CBM4 and Ig domain on the N-terminal portion of the enzyme. Lowercase t, a and b indicate the source of the dockerin module (C. thermocellum, A. cellulolyticus and B. cellulosolvens respectively).