781
Threonine 78 lies within the D-box of the v-erb A protein , a region thought to mediate receptor-receptor dimerizations , and is not in physical proximity to the serine at position 61 .
 protein: v-erb A; protein: D-box; protein: position 61; protein: v-erb A protein
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:
 protein: v-erb A; protein: D-box; protein: position 61; protein: v-erb A protein