Eukaryotic ribosomal RNA determinants of aminoglycoside resistance and their role in translational fidelity
Eukaryotic ribosomal RNA determinants of aminoglycoside resistance and their role in translational fidelity
复制标题
DOI：
10.1261/rna.805208
复制
发表时间：
2008-01-01
期刊：
影响因子：
4.5
通讯作者：
Bedwell, David M.
中科院分区：
文献类型：
--
作者：
Fan-Minogue, Hua;Bedwell, David M.
最近对原核生物核糖体的研究极大地增加了我们对核糖体RNA（rRNA）结构、功能中心及其与抗生素相互作用的了解。然而，关于rRNA功能在原核和真核核糖体之间的差异知之甚少。核心解码位点在酵母和人类18S rRNA中是相同的，这表明在酵母rRNA突变体的研究中获得的见解可以提供关于两个物种中核糖体功能的信息。在这项研究中，我们研究了18S rRNA的核糖体功能和氨基糖苷类药物的敏感性在酿酒酵母细胞表达突变体核糖体的同质群体的关键核苷酸的解码位点的重要性。我们发现，残基G577，A1755和A1756（分别对应于大肠杆菌残基G530，A1492和A1493）是细胞活力所必需的。我们还发现，在大肠杆菌中，G1645（A1408）残基在大肠杆菌中也有表达。coli）和A1754（E.大肠杆菌）都对氨基糖苷类抗生素耐药性做出显著和独特的贡献。此外，我们发现，在这些残基的突变不改变基础水平的翻译准确性，但影响巴龙霉素诱导的有义密码子和通读终止密码子的误读。这项研究代表了最全面的突变分析的真核生物的解码位点的日期，并表明，许多基本功能的解码位点的功能是保守的原核生物和真核生物之间。
Recent studies of prokaryotic ribosomes have dramatically increased our knowledge of ribosomal RNA (rRNA) structure, functional centers, and their interactions with antibiotics. However, much less is known about how rRNA function differs between prokaryotic and eukaryotic ribosomes. The core decoding sites are identical in yeast and human 18S rRNAs, suggesting that insights obtained in studies with yeast rRNA mutants can provide information about ribosome function in both species. In this study, we examined the importance of key nucleotides of the 18S rRNA decoding site on ribosome function and aminoglycoside susceptibility in Saccharomyces cerevisiae cells expressing homogeneous populations of mutant ribosomes. We found that residues G577, A1755, and A1756 (corresponding to Escherichia coli residues G530, A1492, and A1493, respectively) are essential for cell viability. We also found that residue G1645 (A1408 in E. coli) and A1754 (G1491 in E. coli) both make significant and distinct contributions to aminoglycoside resistance. Furthermore, we found that mutations at these residues do not alter the basal level of translational accuracy, but influence both paromomycin-induced misreading of sense codons and readthrough of stop codons. This study represents the most comprehensive mutational analysis of the eukaryotic decoding site to date, and suggests that many fundamental features of decoding site function are conserved between prokaryotes and eukaryotes.