11071
Examination of the basal factors interacting with the 21 bp repeat elements through electrophoretic mobility shift (EMS) analyses has demonstrated the formation of DNA-protein complexes common to each of the 21 bp repeats ( C1-C3 ) as well as three DNA-protein complexes specific to the promoter proximal (pp) repeat ( U1 ( U1A/U1B ) and U2 ; 1-4).
 ( DNA: U2, None) , ( protein: DNA-protein complexes, None) , ( DNA: 21 bp repeat elements, None) , ( DNA: 21 bp repeats, None) , ( DNA: C1-C3, None) , ( DNA: U1A/U1B, None) , ( protein: DNA-protein complexes, None) , ( protein: basal factors, None) , ( DNA: U1, None) , ( DNA: promoter proximal (pp) repeat, 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: U2, None) , ( protein: DNA-protein complexes, None) , ( DNA: 21 bp repeat elements, None) , ( DNA: 21 bp repeats, None) , ( DNA: C1-C3, None) , ( DNA: U1A/U1B, None) , ( protein: DNA-protein complexes, None) , ( protein: basal factors, None) , ( DNA: U1, None) , ( DNA: promoter proximal (pp) repeat, None) 