passages.id: split_5_test_1481_passage
passages.type: progene_text
passages.text: In contrast , substitution of Thr ( 491 ) , which also interacts with the pyrophosphate grouping , had a relatively modest effect on both FAD binding ( 100 - fold decrease ) and catalytic activity ( 2 - fold decrease ) , while the G488L mutant exhibited , respectively , 800 - and 50 - fold decreases in FAD binding and catalytic activity .