玉米SAMS基因的克隆与序列分析

Cloning and Sequence Analysis of SAMS Gene from Zea Mays

腺苷甲硫氨酸合成酶(SAMS)是植物代谢中的1个关键酶,它催化ATP和L-甲硫氨酸合成腺苷甲硫氨酸(SAM)。以玉米为材料,用Trizol一步法提取总RNA,根据已报道的水稻和小麦等的SAMS基因设计1对引物,通过RT-PCR方法获得1条约1.2 kb特异片段,连接T载体测序,其全长共1 191 bp,编码496个氨基酸残基。利用生物信息学分析,结果表明:SAMS蛋白疏水性最大值为1.73,最小值为-2.1;无跨膜域;二级结构主要以无规卷曲为主。

S-adenosyl-L-metnionine synthetase （ SAMS）, which is a key enzyme in the metabolize of the plant, is a ubiquitous enzyme catalyzing the synthesis of S-adenosy-1-methionine （SAM） from ATP and L-methionine. Total RNA was extracted from maize by using Trizol method. A pair of primers were designed and synthesized based on the reported SAMS gene sequence. The specific PCR product was obtained by using the first strand of cDNA as template. The product was linked to T-easy vector and sequenced. The data showed that the PCR product was 1 191 bp, encoding 496 predicted amino acid residues. Homology analysis revealed that the hydrophobicity of SAMS protein was predicted to be 1.73 in maximum and -2. 1 in minimum, and it had not transmembrane regions. The secondary structure was primarily composed of random coil.