Molecular cloning and functional characterization of alpha-humulene synthase, a possible key enzyme of zerumbone biosynthesis in shampoo ginger (Zingiber zerumbet Smith).
Shampoo ginger (Zingiber zerumbet Smith) has a high content and large variety of terpenoids in the essential oil of its rhizome. Here, we report on the isolation of a cDNA clone (ZSS1) encoding alpha-humulene synthase, a possible key enzyme of zerumbone biosynthesis. This clone contains an open reading frame of 1,644 bp and is predicted to encode a protein of 548 amino acids with a calculated molecular mass of 64.5 kDa. The deduced amino acid sequence shows 34-63% identity with known sesquiterpene synthases of other angiosperm species. Based on exon-intron organization, ZSS1 is classified as the terpene synthase-III (TPS-III) subfamily. When expressed in Escherichia coli, the recombinant enzyme catalyzed the formation of a major product, alpha-humulene (95%) and a minor by-product, beta-caryophyllene (5%). Introduction of ZSS1 and the foreign mevalonate pathway involved in FPP synthesis into E. coli results in in vivo production of alpha-humulene. Transcript of ZSS1 was detected almost exclusively in rhizomes and was up-regulated in both leaves and rhizomes after treatment with methyl jasmonate (MeJA), suggesting its ecological function in shampoo ginger.
Yu
Fengnian
F
Department of Bioscience, Graduate School of Agriculture, Kinki University, 3327-204 Nakamachi, Nara, 631-8505, Japan.
Okamto
Sho
S
Nakasone
Kaoru
K
Adachi
Kyoko
K
Matsuda
Satoru
S
Harada
Hisashi
H
Misawa
Norihiko
N
Utsumi
Ryutaro
R
D000595:Amino Acid Sequence; D019757:Carbon-Oxygen Lyases / Q000737:chemistry / Q000235:genetics*; D017124:Conserved Sequence; D017931:DNA Primers; D018076:DNA, Complementary / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D020939:Zingiber officinale / Q000201:enzymology / Q000235:genetics*; D008969:Molecular Sequence Data; D000081222:Monocyclic Sesquiterpenes; D016366:Open Reading Frames; D010940:Plant Proteins / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D012717:Sesquiterpenes / Q000378:metabolism*
D017931:DNA Primers; D018076:DNA, Complementary; D018744:DNA, Plant; D000081222:Monocyclic Sesquiterpenes; D010940:Plant Proteins; D012717:Sesquiterpenes; C403304:zerumbone; C042686:humulene; D019757:Carbon-Oxygen Lyases; C530951:alpha-humulene synthase, Zingiber zerumbet