1-Hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate reductase (IDS) is encoded by multicopy genes in gymnosperms Ginkgo biloba and Pinus taeda.
Isoprenoids are synthesized through the condensation of five-carbon intermediates, isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP), derived from two distinct biosynthetic routes: cytosolic mevalonate (MVA) and plastidial 2-C-methyl-D: -erythritol 4-phosphate (MEP) pathways. 1-Hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate reductase (IDS; EC 1.17.1.2), which catalyzes the last step of MEP pathway, was cloned as a multicopy gene from gymnosperms Ginkgo biloba (GbIDS1, GbIDS2, and GbIDS2-1) and Pinus taeda (PtIDS1 and PtIDS2), and characterized. Phylogenetic tree constructed with other plant IDSs demonstrated gymnosperm IDSs were distinctively different from angiosperm IDSs. The gymnosperm IDS clade contained two subclades, one composed of GbIDS1 and PtIDS1, and the other composed of GbIDS2, GbIDS2-1, and PtIDS2. G. biloba IDSs, except GbIDS2-1, successfully complemented Escherichia coli DLYT1, a lytB disruptant, confirming the in vivo competency of isozymes. During the 4 weeks study period, although transcript levels of GbIDS1s were similar both in roots and leaves of cultured G. biloba embryo, the transcripts of GbIDS2 predominantly occurred in the embryo roots, where diterpene ginkgolides are biosynthesized. Levels of PtIDS2 transcripts in the diterpenoid resin-producing wood were 4-5 times higher than those in other tissues. Higher levels of GbIDS1 transcripts were induced by light, whereas those of GbIDS2 were increased by methyl jasmonate treatment. These results strongly imply GbIDS2 and PtIDS2 have high correlation with secondary metabolism. In Arabidopsis transient expression system, N-terminal 100 amino acid residues of GbIDS1 delivered fused GFP protein into chloroplast as well as cytosol and nucleus, whereas those of GbIDS2, GbIDS2-1, and two PtIDSs delivered GFP only into chloroplast.
Kim
Sang-Min
SM
Program in Applied Life Chemistry, Department of Agricultural Biotechnology, Seoul National University, San 56-1, Sillim-dong, Gwanak-gu, Seoul, 151-921, Korea.
Kuzuyama
Tomohisa
T
Kobayashi
Akio
A
Sando
Tomoki
T
Chang
Yung-Jin
YJ
Kim
Soo-Un
SU
D000595:Amino Acid Sequence; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D017343:Genes, Plant / Q000235:genetics*; D020441:Ginkgo biloba / Q000201:enzymology* / Q000235:genetics* / Q000528:radiation effects; D008027:Light; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000737:chemistry / Q000235:genetics*; D010802:Phylogeny; D041603:Pinus taeda / Q000201:enzymology* / Q000235:genetics* / Q000528:radiation effects; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism
D010940:Plant Proteins; D018749:RNA, Plant; D010088:Oxidoreductases