8SSF

Minimal protein-only/RNA-free Ribonuclease P from Hydrogenobacter thermophilus

8SSF の概要

• エントリーDOI: 10.2210/pdb8ssf/pdb
• 分子名称: RNA-free ribonuclease P, SULFATE ION (3 entities in total)
• 機能のキーワード: rna-free ribonuclease p, hydrolase, nuclease, rna binding protein
• 由来する生物種: Hydrogenobacter thermophilus TK-6
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 45253.69

構造登録者

Mendoza, J.,Mallik, L.,Wilhelm, C.A.,Koutmos, M. (登録日: 2023-05-08, 公開日: 2023-10-18, 最終更新日: 2023-11-22)

主引用文献

Wilhelm, C.A.,Mallik, L.,Kelly, A.L.,Brotzman, S.,Mendoza, J.,Anders, A.G.,Leskaj, S.,Castillo, C.,Ruotolo, B.T.,Cianfrocco, M.A.,Koutmos, M.
Bacterial RNA-free RNase P: Structural and functional characterization of multiple oligomeric forms of a minimal protein-only ribonuclease P.
J.Biol.Chem., 299:105327-105327, 2023

PubMed Abstract: tRNAs are typically transcribed with extended 5' and 3' ends that must be removed before they attain their active form. One of the first steps of tRNA processing in nearly every organism is the removal of the 5' leader sequence by ribonuclease P (RNase P). Here, we investigate a recently discovered class of RNase P enzymes, Homologs of Aquifex RNase P (HARPs). In contrast to other RNase Ps, HARPs consist only of a metallonuclease domain and lack the canonical substrate recognition domain essential in other classes of proteinaceous RNase P. We determined the cryo-EM structure of Aquifex aeolicus HARP (Aq880) and two crystal structures of Hydrogenobacter thermophilus HARP (Hth1307) to reveal that both enzymes form large ring-like assemblies: a dodecamer in Aq880 and a tetradecamer in Hth1307. In both oligomers, the enzyme active site is 42 Å away from a positively charged helical region, as seen in other protein-only RNase P enzymes, which likely serves to recognize and bind the elbow region of the pre-tRNA substrate. In addition, we use native mass spectrometry to confirm and characterize the previously unreported tetradecamer state. Notably, we find that multiple oligomeric states of Hth1307 are able to cleave pre-tRNAs. Furthermore, our single-turnover kinetic studies indicate that Hth1307 cleaves pre-tRNAs from multiple species with a preference for native substrates. These data provide a closer look at the nuanced similarities and differences in tRNA processing across disparate classes of RNase P.

PubMed: 37806495
DOI: 10.1016/j.jbc.2023.105327

実験手法

X-RAY DIFFRACTION (2.5 Å)