Gantt J S, Thompson M D
Department of Plant Biology, University of Minnesota, St. Paul 55108.
J Biol Chem. 1990 Feb 15;265(5):2763-7.
We have isolated cDNA clones specific for Arabidopsis thaliana cytosolic ribosomal protein S11 and plastid ribosomal protein CS17, both of which are encoded in the nuclear genome, through the use of the corresponding soybean and pea cDNAs as probes, respectively. The nucleotide sequences of all four cDNAs were determined. The amino acid sequences derived from these cDNA sequences show that the soybean and A. thaliana S11 cDNAs encode proteins that are homologous to rat ribosomal protein S11 and that the pea and A. thaliana CS17 cDNAs encode proteins that are homologous to Escherichia coli ribosomal protein S17. The plant S11 cytosolic ribosomal proteins also show significant sequence similarity to both E. coli ribosomal protein S17 and plastid CS17 indicating that these are all related proteins. Comparison of A. thaliana CS17 with A. thaliana S11 and with E. coli S17 suggests that CS17 is more related to S17 than it is to S11. These results support the idea that the gene encoding CS17 was derived from a prokaryotic endosymbiont and not from a duplication of the eukaryotic S11 gene.
我们分别使用相应的大豆和豌豆cDNA作为探针，分离出了拟南芥胞质核糖体蛋白S11和质体核糖体蛋白CS17的特异性cDNA克隆，这两种蛋白均由核基因组编码。测定了所有四个cDNA的核苷酸序列。从这些cDNA序列推导的氨基酸序列表明，大豆和拟南芥S11 cDNA编码的蛋白质与大鼠核糖体蛋白S11同源，豌豆和拟南芥CS17 cDNA编码的蛋白质与大肠杆菌核糖体蛋白S17同源。植物S11胞质核糖体蛋白与大肠杆菌核糖体蛋白S17和质体CS17也显示出显著的序列相似性，表明它们都是相关蛋白。拟南芥CS17与拟南芥S11以及大肠杆菌S17的比较表明，CS17与S17的关系比与S11的关系更密切。这些结果支持了编码CS17的基因来源于原核内共生体而非真核S11基因复制的观点。
