Molecular cloning and characterization of S-adenosylmethionine synthetase gene from Lycoris radiata
Molecular cloning and characterization of S-adenosylmethionine synthetase gene from Lycoris radiata
复制标题
石蒜S-腺苷甲硫氨酸合成酶基因的分子克隆及鉴定
DOI：
10.1007/s11033-012-2168-9
复制
发表时间：
2013-02-01
影响因子：
2.8
通讯作者：
Peng, Feng
中科院分区：
文献类型：
--
作者：
Li, Xiao-Dan;Xia, Bing;Peng, Feng
S-腺苷甲硫氨酸合成酶催化合成腺苷甲硫氨酸，腺苷甲硫氨酸是所有细胞生物的重要分子。它也被认为在植物的耐盐性中起着重要作用。在此，我们克隆了石蒜SAM合成酶基因LrSAMS，以确定其生物学功能。该基因编码401个氨基酸的蛋白质，计算相对分子质量为43.9 kDa。对LrSAMS蛋白的氨基酸序列分析表明，该蛋白与拟南芥和水稻等其他生物的SAM合成酶具有很高的序列同源性。推导的LrSAMS蛋白含有与SAM合成酶功能密切相关的保守氨基酸残基和序列基序。此外，盐处理显著诱导了LrSAMS基因的转录水平，表明LrSAMS基因可能在L.Radiata的耐盐性中起重要作用。将LrSAMS的完整ORF插入表达载体pET-29a(+)，转化大肠杆菌BL21(DE3)。转基因菌株和空白对照菌株生长曲线的差异表明，过表达LrSAMS可以为工程菌在高盐浓度下提供生长优势。
S-adenosylmethionine (SAM) synthetase catalyzes the synthesis of SAM, a molecule important for all cellular organisms. It is also considered to play an important role in salt tolerance of plants. Here, we cloned a Lycoris radiata (L. radiata) SAM synthetase gene LrSAMS to determine its biological function. The gene encodes a protein of 401 amino acids with a calculated molecular weight of 43.9 kDa. Amino acid sequence analysis of the deduced protein LrSAMS reveals high sequence identity to SAM synthetases from other organisms, such as Arabidopsis thaliana and Oryza sativa. The deduced LrSAMS protein contains conserved amino acids residues and sequences motifs that closely related to the function of SAM synthetase. Otherwise, the transcript levels of LrSAMS were significantly induced by NaCl treatment in L. radiata leaves, which implied that LrSAMS might play an important role in tolerance to salt stress in L.radiata. Complete ORF of LrSAMS was inserted into expression vector pET-29a(+) and transformed into Escherichia coli BL21 (DE3). The difference between the growth curve of the transgenic strain and control strain with blank vector showed that over-expressing LrSAMS could provide growth advantage to the engineered strain in high salt concentration.