title: The Ycf54 protein is part of the membrane component of Mg-protoporphyrin IX monomethyl ester cyclase from barley (Hordeum vulgare L.).
abstract: 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, XanL, is found associated with the membrane and another protein, Ycf54, has recently been identified based upon association with XanL. This study describes a deeper analysis of the role of Ycf54 in the enzyme and the localization of the protein in barley plastids. The results clearly demonstrate a strong association of Ycf54 with XanL, absence of Ycf54 from soluble fractions necessary for activity and more evidence for a third membrane localized component of the enzyme.
authors.affiliation: Department of Biology, Illinois Wesleyan University, Bloomington, IL, USA.
authors.forename: David
authors.initials: D
authors.lastname: Bollivar
authors.forename: Ilka
authors.initials: I
authors.lastname: Braumann
authors.forename: Kasper
authors.initials: K
authors.lastname: Berendt
authors.forename: Simon P
authors.initials: SP
authors.lastname: Gough
authors.forename: Mats
authors.initials: M
authors.lastname: Hansson
mesh_terms: D017343:Genes, Plant; D001467:Hordeum / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D010105:Oxygenases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018087:Plastids / Q000378:metabolism; D011524:Protoporphyrins / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D011524:Protoporphyrins; C033434:protoporphyrin IX monomethyl ester; D010105:Oxygenases; C053161:magnesium protoporphyrin monomethyl ester oxidative cyclase
keywords: Mg-protoporphyrin monomethyl ester; chlorophyll; cyclase; etioplast; isocyclic ring