24766
The expression of this gene requires + 1 translational frameshifting and a process of intron splicing for the production of the active protein , designated En - MAPK1 , which contains amino acid substitutions of potential significance for cold - adaptation .
 amino acid
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 amino acid