4871
Both limiting-component transcription assays and DNA binding assays identified the class III gene transcription factor TFIIIB as the principle target of Tax activity .
 ( protein: TFIIIB, None) , ( protein: Tax, None) , ( protein: class III gene transcription factor, 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: TFIIIB, None) , ( protein: Tax, None) , ( protein: class III gene transcription factor, None) 