IGM, CNRS, UMR 8621, Orsay, F 91405, France.
Nucleic Acids Res. 2009 Dec;37(22):7665-77. doi: 10.1093/nar/gkp816.
Important regions of rRNA are rich in nucleotide modifications that can have strong effects on ribosome biogenesis and translation efficiency. Here, we examine the influence of pseudouridylation and 2'-O-methylation on translation accuracy in yeast, by deleting the corresponding guide snoRNAs. The regions analyzed were: the decoding centre (eight modifications), and two intersubunit bridge domains-the A-site finger and Helix 69 (six and five modifications). Results show that a number of modifications influence accuracy with effects ranging from 0.3- to 2.4-fold of wild-type activity. Blocking subsets of modifications, especially from the decoding region, impairs stop codon termination and reading frame maintenance. Unexpectedly, several Helix 69 mutants possess ribosomes with increased fidelity. Consistent with strong positional and synergistic effects is the finding that single deletions can have a more pronounced phenotype than multiple deficiencies in the same region. Altogether, the results demonstrate that rRNA modifications have significant roles in translation accuracy.
rRNA 的重要区域富含核苷酸修饰，这些修饰可能对核糖体生物发生和翻译效率产生强烈影响。在这里，我们通过删除相应的引导 snoRNA，研究了假尿嘧啶化和 2'-O-甲基化对酵母翻译准确性的影响。分析的区域包括：解码中心（八种修饰）和两个亚基间桥结构域——A 位指和 69 号螺旋（六种和五种修饰）。结果表明，许多修饰会影响准确性，其效果范围为野生型活性的 0.3 至 2.4 倍。阻断修饰亚群，特别是来自解码区域的修饰亚群，会损害终止密码子和阅读框的维持。出乎意料的是，几个 69 号螺旋突变体的核糖体具有更高的保真度。位置和协同作用的强烈影响是一致的，即单个缺失比同一区域的多个缺陷具有更明显的表型。总之，这些结果表明 rRNA 修饰在翻译准确性中具有重要作用。
