title: Cloning and characterization of cDNAs coding for Vicia faba polyphenol oxidase.
abstract: Three cDNA clones were isolated which code for the ubiquitous chloroplast enzyme, polyphenol oxidase (PPO), from Vicia faba. Analysis of the cloned DNA reveals that PPO is synthesized with an N-terminal extension of 92 amino acid residues, presumed to be a transit peptide. The mature protein is predicted to have a molecular mass of 58 kDa which is in close agreement to the molecular mass estimated for the in vivo protein upon SDS-PAGE. Differences in the DNA sequence of two full-length and one partial cDNA clones indicate that PPO is encoded by a gene family. Analysis of the deduced amino acid sequence shows that the chloroplast PPO shares homology with the 59 kDa PPOs in glandular trichomes of solanaceous species. A high degree of sequence conservation was found with the copper-binding domains of the 59 kDa tomato PPO as well as hemocyanins and tyrosinases from a wide diversity of taxa.
authors.affiliation: USDA-ARS-Southern Regional Research Center, New Orleans, LA 70179.
authors.forename: J W
authors.initials: JW
authors.lastname: Cary
authors.forename: A R
authors.initials: AR
authors.lastname: Lax
authors.forename: W H
authors.initials: WH
authors.lastname: Flurkey
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004156:Catechol Oxidase / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D004247:DNA / Q000302:isolation & purification; D007887:Fabaceae / Q000201:enzymology / Q000235:genetics*; D008969:Molecular Sequence Data; D010946:Plants, Medicinal; D015183:Restriction Mapping; D017385:Sequence Homology
chemical_list: D004247:DNA; D004156:Catechol Oxidase