title: Identification and characterization of class 1 DXS gene encoding 1-deoxy-D-xylulose-5-phosphate synthase, the first committed enzyme of the MEP pathway from soybean.
abstract: 1-Deoxy-D-xylulose-5-phosphate synthase (DXS) catalyses the first committed step of the 2C-methyl-D-erythritol-4-phosphate (MEP) pathway, which is an alternative isoprenoids biosynthetic route that has been recently discovered. In this work, a DXS1-like cDNA (GmDXS1) was isolated from soybean. The full-length cDNA of GmDXS1 encoded 708 amino acid residues with a predicted molecular mass of 76.4 KD. Sequence alignment showed that GmDXS1 had high homology to known DXS proteins from other plant species and contained the conserved N-terminal plastid transit peptide, the N-terminal thiamine binding domain and pyridine binding DRAG domain. Phylogenetic analysis indicated that GmDXS1 belonged to the plant DXS1 cluster. Southern blot analysis indicated that a single copy of GmDXS1 gene existed in soybean genome. Tissue expression analysis revealed that GmDXS1 expressed in all photosynthetic tissues except pod walls and roots. Green fluorescence analysis with the fusion protein 35S:GmDXS1:GFP suggested that GmDXS1 was localized in plastid. The relatively higher photosynthetic pigment content in transgenic tobacco leaves compared to the control implied that GmDXS1 catalyzed the first potential regulatory step in photosynthetic pigment biosynthesis via the MEP pathway.
authors.affiliation: National Center for Soybean Improvement, National Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Weigang 1, Nanjing, People's Republic of China.
authors.forename: Man
authors.initials: M
authors.lastname: Zhang
authors.forename: Kai
authors.initials: K
authors.lastname: Li
authors.forename: Chunhong
authors.initials: C
authors.lastname: Zhang
authors.forename: Junyi
authors.initials: J
authors.lastname: Gai
authors.forename: Deyue
authors.initials: D
authors.lastname: Yu
mesh_terms: D000595:Amino Acid Sequence; D002338:Carotenoids / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004896:Erythritol / Q000031:analogs & derivatives* / Q000378:metabolism; D018628:Gene Dosage; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D018515:Plant Leaves / Q000201:enzymology; D030821:Plants, Genetically Modified; D018087:Plastids / Q000201:enzymology / Q000235:genetics; D021381:Protein Transport; D017422:Sequence Analysis, DNA; D013025:Glycine max / Q000201:enzymology* / Q000235:genetics; D013347:Subcellular Fractions / Q000201:enzymology; D013403:Sugar Phosphates / Q000378:metabolism*; D014026:Nicotiana / Q000166:cytology / Q000235:genetics; D014166:Transferases / Q000737:chemistry / Q000235:genetics*
chemical_list: C114232:2-C-methylerythritol 4-phosphate; D018076:DNA, Complementary; D013403:Sugar Phosphates; D002734:Chlorophyll; D002338:Carotenoids; D014166:Transferases; C109461:deoxyxylulose-5-phosphate synthase; D004896:Erythritol