title: Functional analysis of the hemK gene product involvement in protoporphyrinogen oxidase activity in yeast.
abstract: The Escherichia coli hemK gene has been described as being involved in protoporphyrinogen oxidase activity; however, there is no biochemical evidence for this. In the context of characterizing the mechanisms of protoporphyrinogen oxidation in the yeast Saccharomyces cerevisiae, we investigated the yeast homolog of HemK, which is encoded by the ORF YNL063w, to find out whether it has any protoporphyrinogen oxidase activity and/or whether it modulates protoporphyrinogen oxidase activity. Phenotype analysis and enzyme activity measurements indicated that the yeast HemK homolog is not involved in protoporphyrinogen oxidase activity. Complementation assays in which the yeast HemK homolog is overproduced do not restore wild-type phenotypes in a yeast strain with deficient protoporphyrinogen oxidase activity. Protein sequence analysis of HemK-related proteins revealed consensus motif for S-adenosyl-methionine-dependent methyltransferase.
authors.affiliation: Département de Microbiologie, Institut Jacques-Monod, UMR 7592-CNRS-Universités Paris, France.
authors.forename: L
authors.initials: L
authors.lastname: Le Guen
authors.forename: R
authors.initials: R
authors.lastname: Santos
authors.forename: J M
authors.initials: JM
authors.lastname: Camadro
mesh_terms: D000595:Amino Acid Sequence; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D008780:Methyltransferases; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D044925:Oxidoreductases Acting on CH-CH Group Donors; D050768:Protoporphyrinogen Oxidase; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D017421:Sequence Analysis
chemical_list: D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins; D010088:Oxidoreductases; D044925:Oxidoreductases Acting on CH-CH Group Donors; D050768:Protoporphyrinogen Oxidase; C509976:MTQ1 protein, S cerevisiae; D008780:Methyltransferases