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The geranylgeranyl
pyrophosphate synthase gene from Ginkgo biloba:
cloning, characterization and functional identification
Wei Wang1, Min Chen2,
Chunxian Yang1, Wanhong Liu1,3,
Xiaozhong Lan3, Zhihua Liao1*
1Laboratory of Natural Products and Metabolic Engineering, Chongqing
Sweetpotato Research Center, Key Laboratory of
Eco-environments in Three Gorges Reservoir Region (Ministry
of Education), School of Life Sciences, Southwest
University, Chongqing 400715, China.
2Laboratory
of Natural Products and Metabolic Engineering, Key
Laboratory of Eco-environments in Three Gorges Reservoir
Region (Ministry of Education), School of Pharmacy,
Southwest University, Chongqing 400715, China.
3Department
of Biology, Chongqing University of Science and Technology,
Chongqing 400042, China.
4Agricultural
and Animal Husbandry College, Tibet University, Linzhi of
Tibet 860000, China.
*Corresponding author. E-mail:
zhliao@swu.edu.cn,
zhihualiao@163.com.
Fax: 86-23-68252365. Tel: 86-23-68367146.
Accepted
30 January, 2009 |
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Geranylgeranyl pyrophosphate synthase (GGDPS, EC: 2.5.1.29)
catalyzes the biosynthesis of 20-carbon geranylgeranyl
pyrophosphate (GGDP), which is a key precursor for
ginkgolides biosynthesis. In order to investigate the role
of GGDP synthase in ginkgolides biosynthesis, we cloned,
characterized and functionally expressed the GGDP synthase
gene from Ginkgo biloba. The genomic DNA fragment of
the GGDPS gene of G. biloba (designated
GbGGDPS GenBank accession number EF646377) was 2135 bp in
length containing an 1176-bp open reading frame (ORF) that
encoded a 391-amino acid polypeptide. Comparative analysis
showed that GbGGDPS had a high similarity to other plant
GGDPSs. Bioinformatic analysis showed that GbGGDPS was an
intron-free gene and its deduced polypeptide contained all
the five conserved domains and functional aspartate-rich
motifs of the polyprenyltransferases. By constructing the
phylogenetic tree of plant GGDPSs, it was found that
plant-derived GGDPSs could be divided into two classes,
angiosperm and gymnosperm classes, which might have evolved
in parallel from the same ancestor. The homology-based
structural modeling showed that GbGGDPS has the typical
structure of GGDPS. The tissue expression profiles of
GbGGDPS indicated that it could express in roots, stems,
leaves, peshes and fruits but at different levels. The
highest expression level of GbGGDPS was found in roots and
peshes while the lowest expression level of GbGGDPS was
found in leaves. Interestingly, it was found that GbGGDPS
had a higher expression level in the treatment of methyl
jasmonate. Finally, the coding sequence of GbGGDPS was
functionally expressed in Escherica coli in which the
β-carotene pathway was reconstructed by genetic
complementation, and the transgenic E. coli showed to
have an activity of GGDP synthase.
Key
words:
Ginkgo biloba, geranylgeranyl pyrophosphate synthase,
cloning, characterization, expression profile, functional
complementation. |
