2802
The germline promoters ( Ko ) located upstream of the J region gene segments of the kappa locus also contain an octamer motif (containing a single base pair mutation and referred to as the variant octamer) which has been shown previously to bind Oct-1 and Oct-2 transcription factors in vitro.
 ( DNA: kappa locus, None) , ( DNA: germline promoters, None) , ( DNA: J region gene segments, None) , ( protein: Oct-2, None) , ( protein: Oct-1, None) , ( DNA: base pair mutation, None) , ( protein: transcription factors, None) , ( DNA: Ko, None) , ( DNA: octamer motif, 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: kappa locus, None) , ( DNA: germline promoters, None) , ( DNA: J region gene segments, None) , ( protein: Oct-2, None) , ( protein: Oct-1, None) , ( DNA: base pair mutation, None) , ( protein: transcription factors, None) , ( DNA: Ko, None) , ( DNA: octamer motif, None) 