title: Identification and functional analyses of two cDNAs that encode fatty acid 9-/13-hydroperoxide lyase (CYP74C) in rice.
abstract: Fatty acid hydroperoxide lyase (HPL), a member of cytochrome P450 (CYP74), produces aldehydes and oxo-acids involved in plant defensive reactions. In monocots, HPL that cleaves 13-hydroperoxides of fatty acids has been reported, but HPL that cleaves 9-hydroperoxides is still unknown. To find this type of HPL, in silico screening of candidate cDNA clones and subsequent functional analyses of recombinant proteins were performed. We found that AK105964 and AK107161 (Genbank accession numbers), cDNAs previously annotated as allene oxide synthase (AOS) in rice, are distinctively grouped from AOS and 13-HPL. Recombinant proteins of these cDNAs produced in Escherichia. coli cleaved both 9- and 13-hydroperoxide of linoleic and linolenic into aldehydes, while having only a trace level of AOS activity and no divinyl ether synthase activity. Hence we designated AK105964 and AK107161 OsHPL1 and OsHPL2 respectively. They are the first CYP74C family cDNAs to be found in monocots.
authors.affiliation: Frontier Laboratories of Value Creation, SAPPORO BREWERIES LTD., Shizuoka, Japan. Hisao.Kuroda@sapporobeer.co.jp
authors.forename: Hisao
authors.initials: H
authors.lastname: Kuroda
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Oshima
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Kaneda
authors.forename: Masachika
authors.initials: M
authors.lastname: Takashio
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D019757:Carbon-Oxygen Lyases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017931:DNA Primers; D018076:DNA, Complementary / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D008969:Molecular Sequence Data; D012275:Oryza / Q000201:enzymology* / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D003577:Cytochrome P-450 Enzyme System; D019757:Carbon-Oxygen Lyases; C505736:fatty acid 9-, 13-hydroperoxide lyase, Oryza sativa