水稻minE基因的克隆及分析

 植物叶绿体与原核生物分裂机制相似，其中MinE蛋白在细菌分裂过程中具有重要作用. 为了研究植物MinE蛋白在叶绿体分裂过程中的功能及其进化，利用RT PCR技术克隆了水稻叶绿体分裂相关基因OsMinE，并在GenBank登录（No. AY496951）.OsMinE基因cDNA全长1 035 bp，其ORF为711 bp，编码236个氨基酸.与原核生物MinE蛋白相比，水稻OsMinE具有明显延伸的N端与C端.其N端102个氨基酸残基为预测的叶绿体导肽序列,C端延伸保守，推测赋予植物MinE蛋白新的功能.植物minE基因结构分析显示，水稻、拟南芥、杨树都仅含有1个内含子，且插入位置及相位相同.这表明,该内含子可能在单子叶、双子叶植物分化前产生.水稻OsMinE基因在大肠杆菌细胞中的表达严重影响了细胞的分裂，初步证明了水稻MinE蛋白与原核细胞MinE蛋白功能类似.水稻OsMinE基因的克隆为进一步研究叶绿体的分裂机制奠定了基础.

Cloning and Analysis of Oryza sativa Chloroplast Division Site Determinant Gene OsMinE

The MinE protein play a key role in selection of the proper division site.To research the function of MinE,minE gene from Oryza sativa was cloned.The verified and sequenced gene was designated as OsMinE,and deposited into public under the accession number AY496951.The amino acid sequences of OsMinE exhibit a little sequence similarity with bacterial MinE proteins and high similarity with plant MinE proteins.To contrast with bacterial MinE proteins and algae MinE protein encoded by plastid DNA,OsMinE has a 102-amino acid N-extension,which were analyzed for the presence of plastid transit peptide by using the neural network-based tool TargetP,ChloroP.Genomic structure comparisons show that exon length and intron position are conserved within Oryza Sativa,Arabidopsis thaliana and Populus tremula.Our data indicates that the emergence of the intron might be prior to that of monocotyledon and dicotyledon.Expression of OsMinE in E.coli resulted in minicell and mix cells,which suggested that MinE is an evolutionary conserved chloroplast division protein.