The alteration in donor/acceptor selectivity fo transglycosylation was explaned from docking. illustrates the modification of subsite occupation of substrate (donor molecule) in the W359F active site. maltopentaose - enzyme complex structures and wild-type enzyme complex structure showed that the glucose units of maltopentaose occupy subsite -3 to +2 in the active site cleft. The bulky side chain of the Trp359 residue prevented the