1931
Sequence analysis revealed that the MEMA protein is identical with a 160 kDa nuclear ' domain rich in serines ' ( DRS ) protein occurring free in the nucleoplasm and in U2 - ribonucleoprotein structures .
 GENE: MEMA protein; GENE: 160 kDa nuclear ' domain rich in serines ' ( DRS ) protein; GENE: U2 - ribonucleoprotein structures
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
Answer:
 GENE: MEMA protein; GENE: 160 kDa nuclear ' domain rich in serines ' ( DRS ) protein; GENE: U2 - ribonucleoprotein structures