Cellohexaose docking to Man5B. A. Illustration of cellohexaose (surface represented in transparent blue) docked to the Man5B (surface represented in transparent gray) catalytic pocket. The system was constructed using VMD. One can observe that the catalytic region forms a tunnel through which the substrate passes. This type of arrangement is not observed in other GH5 enzymes. B. Detailed view of cellohexaose in the Man5B catalytic pocket and of the tunnel (meshed black) formed due to the interaction of side groups of amino acid residues ASN92 (right side) and TRP210 (left side). C. Detailed view of catalytic site slightly rotated relative to the view in B. The arrows indicate the pockets where the CH2OH group is accommodated. Black arrow: CH2OH group of carbohydrate at position -1; red arrow: CH2OH group of carbohydrate at position 1. Accommodation of both cellohexaose and mannohexaose conformations in the enzyme are very similar.