14384
UV cross-linking experiments suggested that a distinct E2F DNA-binding protein is uniquely associated with the S-phase p107 complex and is not associated with Rb .
 ( protein: p107, None) , ( protein: Rb, None) , ( protein: E2F, None) , ( protein: S-phase p107 complex, 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:
 ( protein: p107, None) , ( protein: Rb, None) , ( protein: E2F, None) , ( protein: S-phase p107 complex, None) 