Department of Physics, The Ohio State University, Columbus, OH, USA.
Center for RNA Biology, The Ohio State University, Columbus, OH, USA.
RNA Biol. 2021 Nov 12;18(sup2):856-865. doi: 10.1080/15476286.2021.2000793. Epub 2021 Nov 23.
In most bacteria, the three ribosomal RNAs (rRNAs) are encoded together in each of several near-identical operons. As soon as the nascent precursor rRNA emerges from RNA polymerase, ribosome assembly begins. This process entails ribosomal protein binding, rRNA folding, rRNA modification, and rRNA processing. In the model organisms and , rRNA processing results in similar mature rRNAs, despite substantial differences in the cohort of RNAses involved. A recent study of , a member of the phylum Bacteroidota (formerly Bacteroidetes), revealed that helix H1 of 23S rRNA is absent from ribosomes, apparently a consequence of rRNA maturation. In this work, we mined RNA-seq data from 19 individual organisms and ocean metatranscriptomic samples to compare rRNA processing across diverse bacterial lineages. We found that mature ribosomes from multiple clades lack H1, and typically these ribosomes also lack an encoded H98. For all groups analysed, H1 is predicted to form in precursor rRNA as part of a longer leader-trailer helix. Hence, we infer that evolutionary loss of H98 sets the stage for H1 removal during 50S subunit maturation.
在大多数细菌中，三个核糖体 RNA（rRNA）被编码在每个几个几乎相同的操纵子中。一旦新生的前体 rRNA从 RNA 聚合酶中出现，核糖体组装就开始了。这个过程包括核糖体蛋白结合、rRNA 折叠、rRNA 修饰和 rRNA 加工。在模型生物 和 中，尽管涉及的 RNA 酶的群体存在很大差异，但 rRNA 加工导致相似的成熟 rRNA。最近对 的研究，一个门 Bacteroidota（以前称为 Bacteroidetes）的成员，揭示了 23S rRNA 的螺旋 H1 不存在于核糖体中，显然是 rRNA 成熟的结果。在这项工作中，我们从 19 个个体生物和海洋宏转录组样本中挖掘 RNA-seq 数据，以比较不同细菌谱系的 rRNA 加工。我们发现，来自多个进化枝的成熟核糖体缺乏 H1，而且这些核糖体通常也缺乏编码的 H98。对于所有分析的群体，H1 被预测在前体 rRNA 中形成一个更长的前导-尾随螺旋的一部分。因此，我们推断 H98 的进化丢失为 H1 在 50S 亚基成熟过程中的去除奠定了基础。
