14088
Differences in LTR sequence also resulted in differences in transcription factor recruitment to cis-acting sites within the U3 region of the LTR , as demonstrated by electrophoretic mobility shift assays .
 ( DNA: LTR sequence, None) , ( DNA: LTR, None) , ( DNA: U3 region, None) , ( DNA: cis-acting sites, None) , ( DNA: LTR, 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: LTR sequence, None) , ( DNA: LTR, None) , ( DNA: U3 region, None) , ( DNA: cis-acting sites, None) , ( DNA: LTR, None) 