Carbohydrate Binding Modules: Biochemical Properties and Novel Applications

3D structures of plant and bacterial CBMs. (A to C) Structure of bacterial (A) and plant (B and C) CBMs (created with UCSF CHIMERA extensible molecular modeling system software, University of California, San Francisco) (154). β-Sheet fragments appear as blue strips; the amino acids at the binding sites are indicated in red (for CBD family III, they are Asp56, His57, Tyr67, Arg112, and Trp118 [planar] and Arg40, Tyr42, Tyr91, Glu93, Tyr127, Thr142, and Tyr144 [groove]; for β-expansin, they are Asn159, Tyr160, Trp194, Arg199, and Asp201; for the expansin-like protein, they are His16, Glu48, Asp55, and Glu57). (D to F) Alignment of the 3D backbone structures of the CBD family III (yellow) and expansin-like (orange) proteins. Selected homologous amino acids in panels D to F are indicated in blue (CBD family III) and green (expansin-like protein) (for groove I, they are Arg40, Tyr127, and Thr142 [CBD family III] and His16, Leu20, and Val51 [expansin-like protein]; for groove II, they are Lys3, Glu5, Lys23, Thr25, Gln108, Gln110, and Phe135 [CBD family III] and Glu30, Glu32, Trp41, Arg67, Leu69, Val77, and Asp79 [expansin-like protein]). Planar amino acids of CBD family III in F are indicated in red.