Tapprich W E, Dahlberg A E
Division of Biological Sciences, University of Montana, Missoula 59812.
EMBO J. 1990 Aug;9(8):2649-55. doi: 10.1002/j.1460-2075.1990.tb07447.x.
A single base substitution mutation from guanine to cytosine was constructed at position 2661 of Escherichia coli 23S rRNA and cloned into the rrnB operon of the multi-copy plasmid pKK3535. The mutant plasmid was transformed into E.coli to determine the effect of the mutation on cell growth as well as the structural and functional properties of the mutant ribosomes in vivo and in vitro. The results show that the mutant ribosomes have a slower elongation rate and an altered affinity for EF-Tu-tRNA-GTP ternary complex. This supports previous findings which indicated that position 2661 is part of a region of 23S rRNA that forms a recognition site for binding of the ternary complex in the ribosomal A site. Combinations of the 2661 mutation with various mutations in ribosomal protein S12 also demonstrate that elements of both ribosomal subunits work in concert to form this binding site.
在大肠杆菌23S rRNA的2661位构建了一个从鸟嘌呤到胞嘧啶的单碱基替换突变，并克隆到多拷贝质粒pKK3535的rrnB操纵子中。将突变体质粒转化到大肠杆菌中，以确定该突变对细胞生长以及突变核糖体在体内和体外的结构和功能特性的影响。结果表明，突变核糖体的延伸速率较慢，对EF-Tu-tRNA-GTP三元复合物的亲和力发生改变。这支持了先前的研究结果，即2661位是23S rRNA中形成核糖体A位点三元复合物结合识别位点区域的一部分。2661位突变与核糖体蛋白S12中的各种突变的组合也表明，两个核糖体亚基的元件协同作用形成该结合位点。
