Molecular cloning and characterization of a cDNA encoding the gibberellin biosynthetic enzyme ent-kaurene synthase B from pumpkin (Cucurbita maxima L.)

Shinjiro Yamaguchi, Tamio Saito, Hiroshi Abe, Hisakazu Yamane, Noboru Murofushi, Yuji Kamiya

    Research output: Contribution to journalReview articlepeer-review

    100 Citations (Scopus)

    Abstract

    The first committed step in the formation of diterpenoids leading to gibberellin (GA) biosynthesis is the conversion of geranylgeranyl diphosphate (GGDP) to ent-kaurene. ent-Kaurene synthase A (KSA) catalyzes the conversion of GGDP to copalyl diphosphate (CDP), which is subsequently converted to ent-kaurene by ent-kaurene synthase B (KSB). A full-length KSB cDNA was isolated from developing cotyledons in immature seeds of pumpkin (Cucurbita maxima L.). Degenerate oligonucleotide primers were designed from the amino acid sequences obtained from the purified protein to amplify a cDNA fragment, which was used for library screening. The isolated full-length cDNA was expressed in Escherichia coli as a fusion protein, which demonstrated the KSB activity to cyclize [3H]CDP to [3H]ent-kaurene. The KSB transcript was most abundant in growing tissues, but was detected in every organ in pumpkin seedlings. The deduced amino acid sequence shares significant homology with other terpene cyclases, including the conserved DDXXD motif, a putative divalent metal ion-diphosphate complex binding site. A putative transit peptide sequence that may target the translated product into the plastids is present in the N-terminal region.

    Original languageEnglish
    Pages (from-to)203-213
    Number of pages11
    JournalPlant Journal
    Volume10
    Issue number2
    DOIs
    Publication statusPublished - 1996 Aug 1

    ASJC Scopus subject areas

    • Genetics
    • Plant Science
    • Cell Biology

    Fingerprint Dive into the research topics of 'Molecular cloning and characterization of a cDNA encoding the gibberellin biosynthetic enzyme ent-kaurene synthase B from pumpkin (Cucurbita maxima L.)'. Together they form a unique fingerprint.

    Cite this