title: Cloning and functional characterization of an O-acetylserine(thiol)lyase-encoding gene in wild soybean (Glycine soja).
abstract: The terminal step of soybean cysteine synthesis is catalyzed by O-acetylserine(thiol)lyase (OAS-TL, EC 2.5.1.47). In this study, we isolated and characterized an OAS-TL gene from a wild soybean material (designated as GsOAS-TL1). GsOAS-TL1 cDNA sequence showed strict conservation at both nucleotide and amino acid levels compared with that from cultivated soybean. Genomic structure analysis of GsOAS-TL1 indicated that it contained 10 exons and 9 introns in the coding region with conserved exon sizes and intron locations compared with Arabidopsis thaliana OAS-TL-like genes. Among the complete GsOAS-TL1 cDNA and three part-deletion fragments, only expression of the full-length cDNA could rescue the NK3 cys(-) Escherichia coli auxotroph, which was coherent with the assayed enzyme activity of purified fusion proteins. For RT-PCR analysis in different wild soybean tissues, GsOAS-TL1 showed lower expression in roots and developing seeds, whereas total OAS-TL activity of corresponding tissues showed significantly higher level in seeds than other tissues. To our knowledge, this is the first report on cloning and characterization of an OAS-TL gene from wild soybean. Our results are informative to further elucidate the function and evolution of OAS-TL in soybean.
authors.affiliation: National Center for Soybean Improvement, National Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, PR China.
authors.forename: Chunhong
authors.initials: C
authors.lastname: Zhang
authors.forename: Qingchang
authors.initials: Q
authors.lastname: Meng
authors.forename: Junyi
authors.initials: J
authors.lastname: Gai
authors.forename: Deyue
authors.initials: D
authors.lastname: Yu
mesh_terms: D000595:Amino Acid Sequence; D019757:Carbon-Oxygen Lyases / Q000235:genetics*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D007887:Fabaceae / Q000201:enzymology* / Q000235:genetics; D017343:Genes, Plant; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D011994:Recombinant Proteins; C018725:O-acetylhomoserine (thiol)-lyase; D019757:Carbon-Oxygen Lyases