11500
Dexamethasone (10(-8) M) repressed chloramphenicol acetyltransferase ( CAT ) production by 75% in the wild-type fragment but not in a deletion mutant lacking the 19-bp site .
 ( DNA: wild-type fragment, None) , ( DNA: 19-bp site, None) , ( protein: chloramphenicol acetyltransferase, None) , ( protein: CAT, None) , ( DNA: deletion mutant, None) 
Locate the role in the text that participated in the event based on the event type and return it in the event list. 
 Option: Event type: RNA,cell type,protein,cell line,DNA, Arguments type: . 
Text: {0} 
Answer:
 ( DNA: wild-type fragment, None) , ( DNA: 19-bp site, None) , ( protein: chloramphenicol acetyltransferase, None) , ( protein: CAT, None) , ( DNA: deletion mutant, None) 