Deshmukh M, Stark J, Yeh L C, Lee J C, Woolford J L
Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
J Biol Chem. 1995 Dec 15;270(50):30148-56. doi: 10.1074/jbc.270.50.30148.
Yeast ribosomal protein L1 binds to 5 S rRNA and can be released from 60 S ribosomal subunits as an intact ribonucleoprotein particle. To identify residues important for binding of Saccharomyces cerevisiae rpL1 to 5 S rRNA and assembly into functional ribosomes, we have isolated mutant alleles of the yeast RPL1 gene by site-directed and random mutagenesis. The rpl1 mutants were assayed for association of rpL1 with 5 S rRNA in vivo and in vitro and assembly of rpL1 into functional 60 S ribosomal subunits. Consistent with previous data implicating the importance of the carboxyl-terminal 47 amino acids of rpL1 for binding to 5 S rRNA in vitro, we find that deletion of the carboxyl-terminal 8, 25, or 44 amino acids of rpL1 confers lethality in vivo. Missense mutations elsewhere in rpL1 also affect its function, indicating that multiple regions of rpL1 are important for its association with 5 S rRNA and assembly into ribosomes.
酵母核糖体蛋白L1可与5S rRNA结合，并能作为完整的核糖核蛋白颗粒从60S核糖体亚基上释放出来。为了鉴定酿酒酵母rpL1与5S rRNA结合以及组装成功能性核糖体的重要残基，我们通过定点诱变和随机诱变分离出了酵母RPL1基因的突变等位基因。对rpl1突变体进行了体内和体外rpL1与5S rRNA结合以及rpL1组装成功能性60S核糖体亚基的检测。与之前的数据一致，之前的数据表明rpL1的羧基末端47个氨基酸在体外与5S rRNA结合中很重要，我们发现缺失rpL1羧基末端的8、25或44个氨基酸在体内会导致致死性。rpL1其他位置的错义突变也会影响其功能，这表明rpL1的多个区域对其与5S rRNA结合以及组装成核糖体很重要。
