Aminopyrimidine aminohydrolase

Aminopyrimidine aminohydrolase (EC 3.5.99.2, thiaminase, thiaminase II, tenA (gene)) is an enzyme with systematic name 4-amino-5-aminomethyl-2-methylpyrimidine aminohydrolase. This enzyme catalyses the following chemical reaction

(1) 4-amino-5-aminomethyl-2-methylpyrimidine + H₂O ⇌ 4-amino-5-hydroxymethyl-2-methylpyrimidine + ammonia (2) thiamine + H₂O ⇌ 4-amino-5-hydroxymethyl-2-methylpyrimidine + 5-(2-hydroxyethyl)-4-methylthiazole

This enzyme was previously known as thiaminase II.