9899
We report that removal of the N-terminal 151 amino acids , encompassing all of the acidic domain but leaving intact the proline / serine / threonine -rich domain , results in a mutant protein with potent suppressive properties for MHC class II expression .
 ( protein: MHC class II, None) , ( protein: acidic domain, None) , ( protein: proline / serine / threonine -rich domain, None) , ( protein: N-terminal 151 amino acids, 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: MHC class II, None) , ( protein: acidic domain, None) , ( protein: proline / serine / threonine -rich domain, None) , ( protein: N-terminal 151 amino acids, None) 