4,4'-Diapophytoene synthase

4,4'-diapophytoene synthase (, dehydrosqualene synthase, DAP synthase, C30 carotene synthase, CrtM) is an enzyme with systematic name farnesyl-diphosphate:farnesyl-diphosphate farnesyltransferase (4,4'-diapophytoene forming). This enzyme catalyses the following chemical reaction


 * 2 (2E,6E)-farnesyl diphosphate $$\rightleftharpoons$$ 4,4'-diapophytoene + 2 diphosphate (overall reaction)
 * (1a) 2 (2E,6E)-farnesyl diphosphate $$\rightleftharpoons$$ diphosphate + presqualene diphosphate
 * (1b) presqualene diphosphate $$\rightleftharpoons$$ 4,4'-diapophytoene + diphosphate

This enzyme requires Mn2+. It is present in Staphylococcus aureus and some other bacteria such as Heliobacillus sp.