抗草甘膦水稻突变体osgr-1 EPSPS基因克隆及生物信息学分析

Bioinformatic Analysis of EPSPS Gene from the Rice Resistant Mutant Osgr-1 of Glyphosate

为深入研究抗草甘膦水稻突变体osgr-1中编码5-烯醇式丙酮酸莽草酸-3-磷酸合成酶基因EPSPS的结构与功能,利用生物信息学分析方法对EPSPS基因结构进行分析,对其编码产物功能进行预测。对克隆的EPSPS基因序列分析表明,osgr-1突变体EPSPS基因中CDS序列发生了3个位点的突变,分别为第226位核苷酸残基C变为G,引起编码蛋白226位脯氨酸(Pro)变成丙氨酸(Ala);第301位核苷酸残基G变为T,导致编码产物311位丙氨酸(Ala)变为丝氨酸(Ser);第311位核苷酸残基A变为C,导致编码蛋白中多少位的谷氨酸(Glu)变为丙氨酸(Ala)。该突变基因编码蛋白含511个aa,Mr为53,823kDa,分子式为C_(2373)H_(3867)N_(659)O_(721)S_(23),等电点为8.33,为疏水性蛋白,定位于叶绿体上且不存在信号肽;其二级结构中β-转角、α螺旋和无规则卷曲分别占31.6%、17.7%和0.7%;三级结构呈单聚体,由2个亚基组成,有4个氯离子、3个镁离子、1个磷酸根离子的结合位点和2个结构域。

To better understand the function of EPSPS gene from the mutant osgr-1 of resistant Glyphosate rice,the bioinformatic analysis method was used to predict their domains and functions. The results showed that the CDS of EPSPS gene sequence was found within three point mutations, respectively,the 226 th base was changed from C to G which encodes alanine instead of proline;301 st base was changed from G into T which encodes serine instead of alanine,311 st base was changed from A to C which encodes alanine instead of amino acids,the molecular weight is 53, lectric point is 8.33, and the hydrophob utamic acid.The EPSPS gene encoding protein include 511 3 kDa, Molecular formula is C2373 H3867N659 O721 S23.The isoe- proteins located in chloroplast and no signal peptide. The secondary structure of protein consisted of β-folds （31.6%）, α-helixes （ 17.7%）, and random coils （50.7%）.The three structure is a monomer, composed of 2 subunits, binding sites with 4 chloride ions,3 magnesium ions, 1 phosphate ions and 2 domains.