17231
Three conserved amino acids ( Y658 , T780 , and S808 ) and two nonconserved residues ( P654 and A809 ) were identified as key determinants of PAM activity .
 Chemical: amino acids
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: amino acids