Tags: Enzyme.
In enzymology a GTP cyclohydrolase IIa (EC 3.5.4.29) is an enzyme that catalyzes the chemical reactionGTP + 3 H2O 2-amino-5-formylamino-6-(5-phosphoribosylamino)pyrimidin-4(3H)-one + 2 phosphateThus the two substrates of this enzyme are GTP and H2O whereas its two products are 2-amino-5-formylamino-6-(5-phosphoribosylamino)pyrimidin-4(3H)-one and phosphate.This enzyme belongs to the family of hydrolases those acting on carbon-nitrogen bonds other than peptide bonds specifically in cyclic amidines.