1170
One of the stretches of prolines in B4-2 closely resembles the ligand for proteins with SH3 domains .
 DNA: B4-2; protein: SH3 domains
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
Answer:
 DNA: B4-2; protein: SH3 domains