The Ycf54 protein is part of the membrane component of Mg-protoporphyrin IX monomethyl ester cyclase from barley (Hordeum vulgare L.)
The biosynthesis of chlorophyll has been demonstrated to require an extensive set of enzymes, the initial stages of which are shared with the synthesis of heme. Of these enzymes, the most enigmatic is the Mg-protoporphyrin IX monomethyl ester cyclase (EC 1.14.13.81). This enzyme requires components found associated with the plastid membrane and the plastid soluble fraction. One of the components,
