title: Isolation of a new dual-functional caffeine synthase gene encoding an enzyme for the conversion of 7-methylxanthine to caffeine from coffee (Coffea arabica L.).
abstract: In coffee and tea plants, caffeine is synthesized from xanthosine via a pathway that includes three methylation steps. We report the isolation of a bifunctional coffee caffeine synthase (CCS1) clone from coffee endosperm by reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) technique using previously reported sequence information for theobromine synthases (CTSs). The predicted amino acid sequences of CCS1 are more than 80% identical to CTSs and are about 40% similar to those of tea caffeine synthase (TCS1). Interestingly, CCS1 has dual methylation activity like tea TCS1.
authors.affiliation: Institute of Agricultural and Forest Engineering, University of Tsukuba, Tsukuba Science City, Ibaraki 305-8572, Japan. koumno@akita-pu.ac.jp
authors.forename: Kouichi
authors.initials: K
authors.lastname: Mizuno
authors.forename: Akira
authors.initials: A
authors.lastname: Okuda
authors.forename: Misako
authors.initials: M
authors.lastname: Kato
authors.forename: Naho
authors.initials: N
authors.lastname: Yoneyama
authors.forename: Hiromi
authors.initials: H
authors.lastname: Tanaka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ashihara
authors.forename: Tatsuhito
authors.initials: T
authors.lastname: Fujimura
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D040503:Coffea / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D008745:Methylation; D008780:Methyltransferases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013805:Theobromine / Q000378:metabolism; D014970:Xanthines / Q000378:metabolism*
chemical_list: D018076:DNA, Complementary; D011994:Recombinant Proteins; D014970:Xanthines; C064273:7-methylxanthine; D008780:Methyltransferases; C120479:caffeine synthase; D013805:Theobromine