12009
These isoforms ( elf-2a and elf-2b ) contain identical RBTN-2 binding regions and DNA-binding domains .
 ( protein: RBTN-2, None) , ( protein: elf-2b, None) , ( protein: DNA-binding domains, None) , ( protein: elf-2a, None) , ( protein: RBTN-2 binding regions, 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: RBTN-2, None) , ( protein: elf-2b, None) , ( protein: DNA-binding domains, None) , ( protein: elf-2a, None) , ( protein: RBTN-2 binding regions, None) 