22517
Acetohydroxyacid synthases ( AHASs ) , which catalyze the first step in the biosynthesis of branched - chain amino acids , are composed of a catalytic subunit ( CSU ) and a regulatory subunit ( RSU ) .
 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