1789
Removal of the carboxy terminus enables ERP to interact with a variety of ets-binding sites including the E74 site , the IgH enhancer pi site , and the lck promoter ets site , suggesting a carboxy-terminal negative regulatory domain .
 ( DNA: lck promoter ets site, None) , ( DNA: ets-binding sites, None) , ( protein: ERP, None) , ( DNA: E74 site, None) , ( protein: carboxy-terminal negative regulatory domain, None) , ( protein: carboxy terminus, None) , ( DNA: IgH enhancer pi site, 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: lck promoter ets site, None) , ( DNA: ets-binding sites, None) , ( protein: ERP, None) , ( DNA: E74 site, None) , ( protein: carboxy-terminal negative regulatory domain, None) , ( protein: carboxy terminus, None) , ( DNA: IgH enhancer pi site, None) 