12768
Much attention has focused on the series of sequence elements upstream of the transcriptional initiation site in the U3 region of the LTR including the Sp1 and NF-kappaB binding sites .
 ( protein: NF-kappaB, None) , ( protein: Sp1, None) , ( DNA: U3 region, None) , ( DNA: LTR, None) , ( DNA: transcriptional initiation site, None) , ( DNA: binding sites, 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: NF-kappaB, None) , ( protein: Sp1, None) , ( DNA: U3 region, None) , ( DNA: LTR, None) , ( DNA: transcriptional initiation site, None) , ( DNA: binding sites, None) 