enzymology Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

, a GTP cyclohydrolase IIa () is an

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

that

catalyzes Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

the

chemical reaction A chemical reaction is a process that leads to the IUPAC nomenclature for organic transformations, chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the pos ...

:GTP + 3 H₂O

\rightleftharpoons

2-amino-5-formylamino-6-(5-phosphoribosylamino)pyrimidin-4(3H)-one + 2 phosphate Thus, 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 In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid . The phosphate or orthophosphate ion is derived from phospho ...

. This enzyme belongs to the family of hydrolases, those acting on carbon-nitrogen bonds other than peptide bonds, specifically in cyclic amidines. The systematic name of this enzyme class is GTP 8,9-hydrolase (phosphate-forming).

References

* EC 3.5.4 Enzymes of unknown structure {{3.5-enzyme-stub