Mutagenesis of the peptidyltransferase center of 23S rRNA: the invariant U2449 is dispensable.
Mutagenesis of the peptidyltransferase center of 23S rRNA: the invariant U2449 is dispensable.
复制标题
23S rRNA 肽基转移酶中心的诱变：不变的 U2449 是可有可无的。
DOI：
10.1093/nar/29.3.710
复制
发表时间：
2001
影响因子：
14.9
通讯作者：
Dahlberg,AE
中科院分区：
文献类型：
--
作者：
O'Connor,M;Lee,WM;Mankad,A;Squires,CL;Dahlberg,AE
U2449是23S rRNA结构域V的中央环中的许多不变残基之一，该区域构成核糖体的肽基转移酶中心的一部分。在大肠杆菌中，该U在转录后被修饰为二氢尿苷（D），并且是大肠杆菌RNA中发现的唯一D修饰。为了分析该碱基及其修饰在核糖体功能中的作用，将所有三种碱基替换构建在thernBoperon的质粒拷贝上，并测定它们在嗜铬染色体操纵子的大肠杆菌菌株中支持细胞生长的能力。两种嘌呤取代突变均不可行。然而，仅表达突变体D2449C rRNA的细胞的生长和抗生素敏感性与野生型没有区别。我们的结论是，虽然嘧啶是必要的位置2449正确的核糖体功能，D修饰是不必要的。
U2449 is one of many invariant residues in the central loop of domain V of 23S rRNA, a region that constitutes part of the peptidyltransferase center of the ribosome. InEscherichia coli, this U is post-transcriptionally modified to dihydrouridine (D) and is the only D modification found inE.colirRNAs. To analyze the role of this base and its modification in ribosomal function, all three base substitutions were constructed on a plasmid copy of therrnBoperon and assayed for their ability to support cell growth in a strain ofE.colilacking chromosomalrrnoperons. Both purine substitution mutations were not viable. However, growth and antibiotic sensitivity of cells expressing only the mutant D2449C rRNA was indistinguishable from wild type. We conclude that while a pyrimidine is required at position 2449 for proper ribosomal function, the D modification is dispensable.