Structural and mechanistic basis of RNA processing by protein-only ribonuclease P enzymes

• Published in: Trends in biochemical sciences (Amsterdam. Regular ed.) Vol. 47; no. 11; pp. 965 - 977
• Main Authors: Bhatta, Arjun, Hillen, Hauke S.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-11-2022
• Subjects: HARP; PRORP; ribonuclease; RNA processing; RNase P; tRNA; RNase P; tRNA; RNA processing; PRORP; HARP; ribonuclease
• ISSN: 0968-0004; 1362-4326
• DOI: 10.1016/j.tibs.2022.05.006

Ribonuclease P (RNase P) enzymes are responsible for the 5′ processing of tRNA precursors. In addition to the well-characterised ribozyme-based RNase P enzymes, an evolutionarily distinct group of protein-only RNase Ps exists. These proteinaceous RNase Ps (PRORPs) can be found in all three domains of life and can be divided into two structurally different types: eukaryotic and prokaryotic. Recent structural studies on members of both families reveal a surprising diversity of molecular architectures, but also highlight conceptual and mechanistic similarities. Here, we provide a comparison between the different types of PRORP enzymes and review how the combination of structural, biochemical, and biophysical studies has led to a molecular picture of protein-mediated tRNA processing.
Ribonuclease P (RNase P) enzymes catalyse endonucleolytic processing of tRNA 5′ ends.Long thought to be universally conserved as ribozymes, recent studies have identified two distinct types of protein-only RNase P enzymes across all domains of life.Structural studies on prototypic members of all types of protein-only RNase P reveal a surprising diversity of molecular architectures.Structures of tRNA-bound protein-only RNase Ps reveal substantial differences in their substrate recognition mechanisms.Despite their differences, comparisons suggest that all protein-only RNase P enzymes use a similar catalytic mechanism for tRNA 5′ processing.