Download MendeleyStructure and mechanistic features of the prokaryotic minimal RNase P.
Feyh, R., Waeber, N.B., Prinz, S., Giammarinaro, P.I., Bange, G., Hochberg, G., Hartmann, R.K., Altegoer, F.(2021) Elife 10
- PubMed: 34180399
- DOI: https://doi.org/10.7554/eLife.70160
- Primary Citation of Related Structures:
7OG5 - PubMed Abstract:
Endonucleolytic removal of 5'-leader sequences from tRNA precursor transcripts (pre-tRNAs) by ribonuclease P (RNase P) is essential for protein synthesis. Beyond RNA-based RNase P enzymes, protein-only versions of the enzyme exert this function in various eukarya (there termed PRORPs) and in some bacteria ( Aquifex aeolicus and close relatives); both enzyme types belong to distinct subgroups of the PIN domain metallonuclease superfamily. Homologs of Aquifex RNase P (HARPs) are also expressed in some other bacteria and many archaea, where they coexist with RNA-based RNase P and do not represent the main RNase P activity. Here, we solved the structure of the bacterial HARP from Halorhodospira halophila by cryo-electron microscopy, revealing a novel screw-like dodecameric assembly. Biochemical experiments demonstrate that oligomerization is required for RNase P activity of HARPs. We propose that the tRNA substrate binds to an extended spike-helix (SH) domain that protrudes from the screw-like assembly to position the 5'-end in close proximity to the active site of the neighboring dimer. The structure suggests that eukaryotic PRORPs and prokaryotic HARPs recognize the same structural elements of pre-tRNAs (tRNA elbow region and cleavage site). Our analysis thus delivers the structural and mechanistic basis for pre-tRNA processing by the prokaryotic HARP system.
Organizational Affiliation:
Institute of Pharmaceutical Chemistry, Philipps-University Marburg, Marburg, Germany.
