title: Heme O biosynthesis in Escherichia coli: the cyoE gene in the cytochrome bo operon encodes a protoheme IX farnesyltransferase.
abstract: The cytochrome bo complex of Escherichia coli is encoded by the cyoABCDE operon and functions as a redox-coupled proton pump. In this study, we have constructed eight cyoE deletion mutants and found that all the mutants were nonfunctional. Spectroscopic and heme analyses of the mutant oxidases revealed that the mutations specifically substituted protoheme IX for heme O present in the high-spin heme binding site. We found also that the overexpression of the cyoE gene in a cyo operon deletion strain resulted in a conversion of protoheme IX to heme O. Since the CyoE protein contains the putative allylic polyprenyldiphosphate binding domain, we concluded that the cyoE gene encodes a novel enzyme, protoheme IX farnesyltransferase, essential for heme O biosynthesis.
authors.affiliation: Department of Biology, Faculty of Science, University of Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Saiki
authors.forename: T
authors.initials: T
authors.lastname: Mogi
authors.forename: Y
authors.initials: Y
authors.lastname: Anraku
mesh_terms: D019883:Alkyl and Aryl Transferases; D000595:Amino Acid Sequence; D003576:Electron Transport Complex IV / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics*; D051231:Farnesyltranstransferase; D017353:Gene Deletion; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D006418:Heme / Q000096:biosynthesis*; D016296:Mutagenesis; D009876:Operon; D017433:Protein Structure, Secondary; D013053:Spectrophotometry; D014166:Transferases / Q000235:genetics* / Q000378:metabolism
chemical_list: C069808:heme O; D006418:Heme; C038862:cytochrome o oxidase; D003576:Electron Transport Complex IV; D014166:Transferases; D019883:Alkyl and Aryl Transferases; D051231:Farnesyltranstransferase