Study on the post-transcriptional regulators of cyanobacteria and chloroplasts

1.单细胞蓝藻聚球藻。PCC6301有两种蛋白质，含有与叶绿体对应的RNA结合域。这是在原核生物中首次发现了RNA结合蛋白(RNPs)，证实了叶绿体RNPs来源于蓝藻。2.对烟草和拟南芥中叶绿体RNPs编码基因的分析表明，叶绿体RNPs可以分为三类。3.叶绿体RNPs被证明与多种叶绿体mRNA物种相关，非核糖体16S rRNA和含有内含子的前tRNAs是稳定的RNA-蛋白质复合体。这一观察结果有力地表明，叶绿体RNPs参与了RNA的加工和RNA的稳定。4.我们发现了新型的RNA结合蛋白。这些新的蛋白质含有一个N端的RNA结合域和C端的富含甘氨酸的结构域，因此它们被命名为RGP(RNA结合富含甘氨酸的蛋白质)。RGP蛋白可能参与了核的转录后调控。5.基于RNA结合区结构和核酸结合特性，我们讨论了上述三种RNA结合蛋白的进化关系。

1.The unicellular cyanobacterium, Synechococcus sp. PCC 6301 has two proteins containing an RNA-binding domain homologous to the chloroplast counterparts. This is the first evidence of RNA-binding proteins (RNPs) in prokaryotes and confirms that chloroplast RNPs are of cyanobacterial origin.2.Analysis of the genes encoding chloroplast RNPs from tobacco and Arabidopsis thaliana indicated that chloroplast RNPs can be categorized into three groups.3.Chloroplast RNPs were demonstrated to be associated with a variety of chloroplast mRNA species, non-ribosomal 16S rRNA and intron-containing pre-tRNAs as stable RNA-protein complexes. This observation strongly suggests that the chloroplast RNPs are involved in RNA processing and RNA stability.4.We discovered novel types of RNA-binding proteins. These novel proteins contain an N-terminal RNA-binding domain and C-terminal glycine-rich domain, therefore they are named RGP (RNA-binding Glycine-rich Proteins). RGP proteins are possibly involved in post-transcriptional regulation in nucleus.5.Based on the RNA-binding domain structures and nucleic acids-binding properties, we discussed evolutionary relationship of the above three types of RNA-binding proteins.