1
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Huang T, Chamberlain A, Zhu J, Harris ME. A minimal RNA substrate with dual fluorescent probes enables rapid kinetics and provides insight into bacterial RNase P active site interactions. RSC Chem Biol 2024; 5:652-668. [PMID: 38966670 PMCID: PMC11221534 DOI: 10.1039/d4cb00049h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 05/17/2024] [Indexed: 07/06/2024] Open
Abstract
Bacterial ribonuclease P (RNase P) is a tRNA processing endonuclease that occurs primarily as a ribonucleoprotein with a catalytic RNA subunit (P RNA). As one of the first ribozymes discovered, P RNA is a well-studied model system for understanding RNA catalysis and substrate recognition. Extensive structural and biochemical studies have revealed the structure of RNase P bound to precursor tRNA (ptRNA) and product tRNA. These studies also helped to define active site residues and propose the molecular interactions that are involved in substrate binding and catalysis. However, a detailed quantitative model of the reaction cycle that includes the structures of intermediates and the process of positioning active site metal ions for catalysis is lacking. To further this goal, we used a chemically modified minimal RNA duplex substrate (MD1) to establish a kinetic framework for measuring the functional effects of P RNA active site mutations. Substitution of U69, a critical nucleotide involved in active site Mg2+ binding, was found to reduce catalysis >500-fold as expected, but had no measurable effect on ptRNA binding kinetics. In contrast, the same U69 mutations had little effect on catalysis in Ca2+ compared to reactions containing native Mg2+ ions. CryoEM structures and SHAPE mapping suggested increased flexibility of U69 and adjacent nucleotides in Ca2+ compared to Mg2+. These results support a model in which slow catalysis in Ca2+ is due to inability to engage U69. These studies establish a set of experimental tools to analyze RNase P kinetics and mechanism and can be expanded to gain new insights into the assembly of the active RNase P-ptRNA complex.
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Affiliation(s)
- Tong Huang
- Department of Chemistry, University of Florida Gainesville FL 32608 USA
| | | | - Jiaqiang Zhu
- Department of Chemistry, University of Florida Gainesville FL 32608 USA
| | - Michael E Harris
- Department of Chemistry, University of Florida Gainesville FL 32608 USA
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2
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Kirsebom LA, Liu F, McClain WH. The discovery of a catalytic RNA within RNase P and its legacy. J Biol Chem 2024; 300:107318. [PMID: 38677513 PMCID: PMC11143913 DOI: 10.1016/j.jbc.2024.107318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 04/12/2024] [Accepted: 04/13/2024] [Indexed: 04/29/2024] Open
Abstract
Sidney Altman's discovery of the processing of one RNA by another RNA that acts like an enzyme was revolutionary in biology and the basis for his sharing the 1989 Nobel Prize in Chemistry with Thomas Cech. These breakthrough findings support the key role of RNA in molecular evolution, where replicating RNAs (and similar chemical derivatives) either with or without peptides functioned in protocells during the early stages of life on Earth, an era referred to as the RNA world. Here, we cover the historical background highlighting the work of Altman and his colleagues and the subsequent efforts of other researchers to understand the biological function of RNase P and its catalytic RNA subunit and to employ it as a tool to downregulate gene expression. We primarily discuss bacterial RNase P-related studies but acknowledge that many groups have significantly contributed to our understanding of archaeal and eukaryotic RNase P, as reviewed in this special issue and elsewhere.
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Affiliation(s)
- Leif A Kirsebom
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden.
| | - Fenyong Liu
- School of Public Health, University of California, Berkeley, California, USA.
| | - William H McClain
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA.
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3
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Zhou B, Wan F, Lei KX, Lan P, Wu J, Lei M. Coevolution of RNA and protein subunits in RNase P and RNase MRP, two RNA processing enzymes. J Biol Chem 2024; 300:105729. [PMID: 38336296 PMCID: PMC10966300 DOI: 10.1016/j.jbc.2024.105729] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 01/12/2024] [Accepted: 01/16/2024] [Indexed: 02/12/2024] Open
Abstract
RNase P and RNase mitochondrial RNA processing (MRP) are ribonucleoproteins (RNPs) that consist of a catalytic RNA and a varying number of protein cofactors. RNase P is responsible for precursor tRNA maturation in all three domains of life, while RNase MRP, exclusive to eukaryotes, primarily functions in rRNA biogenesis. While eukaryotic RNase P is associated with more protein cofactors and has an RNA subunit with fewer auxiliary structural elements compared to its bacterial cousin, the double-anchor precursor tRNA recognition mechanism has remarkably been preserved during evolution. RNase MRP shares evolutionary and structural similarities with RNase P, preserving the catalytic core within the RNA moiety inherited from their common ancestor. By incorporating new protein cofactors and RNA elements, RNase MRP has established itself as a distinct RNP capable of processing ssRNA substrates. The structural information on RNase P and MRP helps build an evolutionary trajectory, depicting how emerging protein cofactors harmonize with the evolution of RNA to shape different functions for RNase P and MRP. Here, we outline the structural and functional relationship between RNase P and MRP to illustrate the coevolution of RNA and protein cofactors, a key driver for the extant, diverse RNP world.
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Affiliation(s)
- Bin Zhou
- Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Institute of Precision Medicine, Shanghai, China
| | - Futang Wan
- Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Institute of Precision Medicine, Shanghai, China
| | - Kevin X Lei
- Shanghai High School International Division, Shanghai, China
| | - Pengfei Lan
- Shanghai Institute of Precision Medicine, Shanghai, China; Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Jian Wu
- Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Institute of Precision Medicine, Shanghai, China.
| | - Ming Lei
- Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Institute of Precision Medicine, Shanghai, China; State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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4
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Zeng D, Abzhanova A, Brown BP, Reiter NJ. Dissecting Monomer-Dimer Equilibrium of an RNase P Protein Provides Insight Into the Synergistic Flexibility of 5' Leader Pre-tRNA Recognition. Front Mol Biosci 2021; 8:730274. [PMID: 34540901 PMCID: PMC8447495 DOI: 10.3389/fmolb.2021.730274] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 08/18/2021] [Indexed: 11/13/2022] Open
Abstract
Ribonuclease P (RNase P) is a universal RNA-protein endonuclease that catalyzes 5' precursor-tRNA (ptRNA) processing. The RNase P RNA plays the catalytic role in ptRNA processing; however, the RNase P protein is required for catalysis in vivo and interacts with the 5' leader sequence. A single P RNA and a P protein form the functional RNase P holoenzyme yet dimeric forms of bacterial RNase P can interact with non-tRNA substrates and influence bacterial cell growth. Oligomeric forms of the P protein can also occur in vitro and occlude the 5' leader ptRNA binding interface, presenting a challenge in accurately defining the substrate recognition properties. To overcome this, concentration and temperature dependent NMR studies were performed on a thermostable RNase P protein from Thermatoga maritima. NMR relaxation (R1, R2), heteronuclear NOE, and diffusion ordered spectroscopy (DOSY) experiments were analyzed, identifying a monomeric species through the determination of the diffusion coefficients (D) and rotational correlation times (τc). Experimental diffusion coefficients and τc values for the predominant monomer (2.17 ± 0.36 * 10-10 m2/s, τ c = 5.3 ns) or dimer (1.87 ± 0.40* 10-10 m2/s, τ c = 9.7 ns) protein assemblies at 45°C correlate well with calculated diffusion coefficients derived from the crystallographic P protein structure (PDB 1NZ0). The identification of a monomeric P protein conformer from relaxation data and chemical shift information enabled us to gain novel insight into the structure of the P protein, highlighting a lack of structural convergence of the N-terminus (residues 1-14) in solution. We propose that the N-terminus of the bacterial P protein is partially disordered and adopts a stable conformation in the presence of RNA. In addition, we have determined the location of the 5' leader RNA in solution and measured the affinity of the 5' leader RNA-P protein interaction. We show that the monomer P protein interacts with RNA at the 5' leader binding cleft that was previously identified using X-ray crystallography. Data support a model where N-terminal protein flexibility is stabilized by holoenzyme formation and helps to accommodate the 5' leader region of ptRNA. Taken together, local structural changes of the P protein and the 5' leader RNA provide a means to obtain optimal substrate alignment and activation of the RNase P holoenzyme.
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Affiliation(s)
- Danyun Zeng
- Department of Chemistry, Marquette University, Milwaukee, WI, United States
| | - Ainur Abzhanova
- Department of Chemistry, Marquette University, Milwaukee, WI, United States
| | - Benjamin P. Brown
- Chemical and Physical Biology Program, Medical Scientist Training Program, Vanderbilt University, Nashville, TN, United States
- Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - Nicholas J. Reiter
- Department of Chemistry, Marquette University, Milwaukee, WI, United States
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5
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Madrigal-Carrillo EA, Díaz-Tufinio CA, Santamaría-Suárez HA, Arciniega M, Torres-Larios A. A screening platform to monitor RNA processing and protein-RNA interactions in ribonuclease P uncovers a small molecule inhibitor. Nucleic Acids Res 2019; 47:6425-6438. [PMID: 30997498 PMCID: PMC6614837 DOI: 10.1093/nar/gkz285] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 04/08/2019] [Accepted: 04/10/2019] [Indexed: 01/10/2023] Open
Abstract
Ribonucleoprotein (RNP) complexes and RNA-processing enzymes are attractive targets for antibiotic development owing to their central roles in microbial physiology. For many of these complexes, comprehensive strategies to identify inhibitors are either lacking or suffer from substantial technical limitations. Here, we describe an activity-binding-structure platform for bacterial ribonuclease P (RNase P), an essential RNP ribozyme involved in 5' tRNA processing. A novel, real-time fluorescence-based assay was used to monitor RNase P activity and rapidly identify inhibitors using a mini-helix and a pre-tRNA-like bipartite substrate. Using the mini-helix substrate, we screened a library comprising 2560 compounds. Initial hits were then validated using pre-tRNA and the pre-tRNA-like substrate, which ultimately verified four compounds as inhibitors. Biolayer interferometry-based binding assays and molecular dynamics simulations were then used to characterize the interactions between each validated inhibitor and the P protein, P RNA and pre-tRNA. X-ray crystallographic studies subsequently elucidated the structure of the P protein bound to the most promising hit, purpurin, and revealed how this inhibitor adversely affects tRNA 5' leader binding. This integrated platform affords improved structure-function studies of RNA processing enzymes and facilitates the discovery of novel regulators or inhibitors.
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Affiliation(s)
- Ezequiel-Alejandro Madrigal-Carrillo
- Department of Biochemistry and Structural Biology, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Carlos-Alejandro Díaz-Tufinio
- Department of Biochemistry and Structural Biology, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
- Tecnologico de Monterrey, Escuela de Ingeniería y Ciencias, Mexico City, Mexico
| | - Hugo-Aníbal Santamaría-Suárez
- Department of Biochemistry and Structural Biology, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Marcelino Arciniega
- Department of Biochemistry and Structural Biology, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Alfredo Torres-Larios
- Department of Biochemistry and Structural Biology, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
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6
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Wan F, Wang Q, Tan J, Tan M, Chen J, Shi S, Lan P, Wu J, Lei M. Cryo-electron microscopy structure of an archaeal ribonuclease P holoenzyme. Nat Commun 2019; 10:2617. [PMID: 31197137 PMCID: PMC6565675 DOI: 10.1038/s41467-019-10496-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Accepted: 05/09/2019] [Indexed: 12/18/2022] Open
Abstract
Ribonuclease P (RNase P) is an essential ribozyme responsible for tRNA 5′ maturation. Here we report the cryo-EM structures of Methanocaldococcus jannaschii (Mja) RNase P holoenzyme alone and in complex with a tRNA substrate at resolutions of 4.6 Å and 4.3 Å, respectively. The structures reveal that the subunits of MjaRNase P are strung together to organize the holoenzyme in a dimeric conformation required for efficient catalysis. The structures also show that archaeal RNase P is a functional chimera of bacterial and eukaryal RNase Ps that possesses bacterial-like two RNA-based anchors and a eukaryal-like protein-aided stabilization mechanism. The 3′-RCCA sequence of tRNA, which is a key recognition element for bacterial RNase P, is dispensable for tRNA recognition by MjaRNase P. The overall organization of MjaRNase P, particularly within the active site, is similar to those of bacterial and eukaryal RNase Ps, suggesting a universal catalytic mechanism for all RNase Ps. Ribonulease P is a conserved ribozyme present in all kingdoms of life that is involved in the 5′ maturation step of tRNAs. Here the authors determine the structure of an archaeal RNase P holoenzyme that reveals how archaeal RNase P recognizes its tRNA substrate and suggest a conserved catalytic mechanism amongst RNase Ps despite structural variability.
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Affiliation(s)
- Futang Wan
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China.,University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, 200031, China.,School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Qianmin Wang
- Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200125, China.,Shanghai Institute of Precision Medicine, Shanghai, 200125, China
| | - Jing Tan
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China.,University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Ming Tan
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China.,University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Juan Chen
- Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200125, China.,Shanghai Institute of Precision Medicine, Shanghai, 200125, China
| | - Shaohua Shi
- Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200125, China.,Shanghai Institute of Precision Medicine, Shanghai, 200125, China
| | - Pengfei Lan
- Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200125, China. .,Shanghai Institute of Precision Medicine, Shanghai, 200125, China.
| | - Jian Wu
- Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200125, China. .,Shanghai Institute of Precision Medicine, Shanghai, 200125, China. .,Shanghai Key Laboratory of Translational Medicine on Ear and Nose diseases, Shanghai, 200125, China.
| | - Ming Lei
- Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200125, China. .,Shanghai Institute of Precision Medicine, Shanghai, 200125, China. .,Key laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
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7
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Wu J, Niu S, Tan M, Huang C, Li M, Song Y, Wang Q, Chen J, Shi S, Lan P, Lei M. Cryo-EM Structure of the Human Ribonuclease P Holoenzyme. Cell 2018; 175:1393-1404.e11. [PMID: 30454648 DOI: 10.1016/j.cell.2018.10.003] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 08/20/2018] [Accepted: 09/28/2018] [Indexed: 12/14/2022]
Abstract
Ribonuclease (RNase) P is a ubiquitous ribozyme that cleaves the 5' leader from precursor tRNAs. Here, we report cryo-electron microscopy structures of the human nuclear RNase P alone and in complex with tRNAVal. Human RNase P is a large ribonucleoprotein complex that contains 10 protein components and one catalytic RNA. The protein components form an interlocked clamp that stabilizes the RNA in a conformation optimal for substrate binding. Human RNase P recognizes the tRNA using a double-anchor mechanism through both protein-RNA and RNA-RNA interactions. Structural comparison of the apo and tRNA-bound human RNase P reveals that binding of tRNA induces a local conformational change in the catalytic center, transforming the ribozyme into an active state. Our results also provide an evolutionary model depicting how auxiliary RNA elements in bacterial RNase P, essential for substrate binding, and catalysis, were replaced by the much more complex and multifunctional protein components in higher organisms.
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Affiliation(s)
- Jian Wu
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200125, China
| | - Shuangshuang Niu
- CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Ming Tan
- CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Chenhui Huang
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200125, China
| | - Mingyue Li
- CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Yang Song
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200125, China
| | - Qianmin Wang
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200125, China
| | - Juan Chen
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200125, China
| | - Shaohua Shi
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200125, China
| | - Pengfei Lan
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200125, China.
| | - Ming Lei
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200125, China; Key laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; National Facility for Protein Science in Shanghai, Zhangjiang Lab, Shanghai 201210, China; Shanghai Science Research Center, Chinese Academy of Sciences, Shanghai 201204, China.
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8
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Lan P, Tan M, Zhang Y, Niu S, Chen J, Shi S, Qiu S, Wang X, Peng X, Cai G, Cheng H, Wu J, Li G, Lei M. Structural insight into precursor tRNA processing by yeast ribonuclease P. Science 2018; 362:science.aat6678. [PMID: 30262633 DOI: 10.1126/science.aat6678] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 09/18/2018] [Indexed: 11/02/2022]
Abstract
Ribonuclease P (RNase P) is a universal ribozyme responsible for processing the 5'-leader of pre-transfer RNA (pre-tRNA). Here, we report the 3.5-angstrom cryo-electron microscopy structures of Saccharomyces cerevisiae RNase P alone and in complex with pre-tRNAPhe The protein components form a hook-shaped architecture that wraps around the RNA and stabilizes RNase P into a "measuring device" with two fixed anchors that recognize the L-shaped pre-tRNA. A universally conserved uridine nucleobase and phosphate backbone in the catalytic center together with the scissile phosphate and the O3' leaving group of pre-tRNA jointly coordinate two catalytic magnesium ions. Binding of pre-tRNA induces a conformational change in the catalytic center that is required for catalysis. Moreover, simulation analysis suggests a two-metal-ion SN2 reaction pathway of pre-tRNA cleavage. These results not only reveal the architecture of yeast RNase P but also provide a molecular basis of how the 5'-leader of pre-tRNA is processed by eukaryotic RNase P.
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Affiliation(s)
- Pengfei Lan
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200125, China
| | - Ming Tan
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences (CAS), Shanghai 200031, China.,University of Chinese Academy of Sciences, CAS, Shanghai 200031, China
| | - Yuebin Zhang
- Laboratory of Molecular Modeling and Design, State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, CAS, Dalian 116023, China
| | - Shuangshuang Niu
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences (CAS), Shanghai 200031, China.,University of Chinese Academy of Sciences, CAS, Shanghai 200031, China.,School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Juan Chen
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200125, China
| | - Shaohua Shi
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200125, China
| | - Shuwan Qiu
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Xuejuan Wang
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Xiangda Peng
- Laboratory of Molecular Modeling and Design, State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, CAS, Dalian 116023, China
| | - Gang Cai
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Hong Cheng
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences (CAS), Shanghai 200031, China
| | - Jian Wu
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200125, China.
| | - Guohui Li
- Laboratory of Molecular Modeling and Design, State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, CAS, Dalian 116023, China.
| | - Ming Lei
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200125, China. .,Key laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.,National Facility for Protein Science in Shanghai, Zhangjiang Laboratory, Shanghai, 201210, China.,Shanghai Science Research Center, CAS, Shanghai, 201204, China
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9
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Zeng D, Brown BP, Voehler MW, Cai S, Reiter NJ. NMR resonance assignments of RNase P protein from Thermotoga maritima. BIOMOLECULAR NMR ASSIGNMENTS 2018; 12:183-187. [PMID: 29450823 PMCID: PMC5871579 DOI: 10.1007/s12104-018-9806-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 01/30/2018] [Indexed: 05/04/2023]
Abstract
Ribonuclase P (RNase P) is an essential metallo-endonuclease that catalyzes 5' precursor-tRNA (ptRNA) processing and exists as an RNA-based enzyme in bacteria, archaea, and eukaryotes. In bacteria, a large catalytic RNA and a small protein component assemble to recognize and accurately cleave ptRNA and tRNA-like molecular scaffolds. Substrate recognition of ptRNA by bacterial RNase P requires RNA-RNA shape complementarity, intermolecular base pairing, and a dynamic protein-ptRNA binding interface. To gain insight into the binding specificity and dynamics of the bacterial protein-ptRNA interface, we report the backbone and side chain 1H, 13C, and 15N resonance assignments of the hyperthermophilic Thermatoga maritima RNase P protein in solution at 318 K. Our data confirm the formation of a stable RNA recognition motif (RRM) with intrinsic heterogeneity at both the N- and C-terminus of the protein, consistent with available structural information. Comprehensive resonance assignments of the bacterial RNase P protein serve as an important first step in understanding how coupled RNA binding and protein-RNA conformational changes give rise to ribonucleoprotein function.
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Affiliation(s)
- Danyun Zeng
- Department of Chemistry, Marquette University, Milwaukee, WI, USA
| | - Benjamin P Brown
- Chemical and Physical Biology Program, Vanderbilt University, Nashville, TN, USA
| | - Markus W Voehler
- Center for Structural Biology, Vanderbilt University, Nashville, TN, USA
| | - Sheng Cai
- Department of Chemistry, Marquette University, Milwaukee, WI, USA
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10
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Mao G, Srivastava AS, Wu S, Kosek D, Lindell M, Kirsebom LA. Critical domain interactions for type A RNase P RNA catalysis with and without the specificity domain. PLoS One 2018; 13:e0192873. [PMID: 29509761 PMCID: PMC5839562 DOI: 10.1371/journal.pone.0192873] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 01/18/2018] [Indexed: 12/17/2022] Open
Abstract
The natural trans-acting ribozyme RNase P RNA (RPR) is composed of two domains in which the catalytic (C-) domain mediates cleavage of various substrates. The C-domain alone, after removal of the second specificity (S-) domain, catalyzes this reaction as well, albeit with reduced efficiency. Here we provide experimental evidence indicating that efficient cleavage mediated by the Escherichia coli C-domain (Eco CP RPR) with and without the C5 protein likely depends on an interaction referred to as the "P6-mimic". Moreover, the P18 helix connects the C- and S-domains between its loop and the P8 helix in the S-domain (the P8/ P18-interaction). In contrast to the "P6-mimic", the presence of P18 does not contribute to the catalytic performance by the C-domain lacking the S-domain in cleavage of an all ribo model hairpin loop substrate while deletion or disruption of the P8/ P18-interaction in full-size RPR lowers the catalytic efficiency in cleavage of the same model hairpin loop substrate in keeping with previously reported data using precursor tRNAs. Consistent with that P18 is not required for cleavage mediated by the C-domain we show that the archaeal Pyrococcus furiosus RPR C-domain, which lacks the P18 helix, is catalytically active in trans without the S-domain and any protein. Our data also suggest that the S-domain has a larger impact on catalysis for E. coli RPR compared to P. furiosus RPR. Finally, we provide data indicating that the absence of the S-domain and P18, or the P8/ P18-interaction in full-length RPR influences the charge distribution near the cleavage site in the RPR-substrate complex to a small but reproducible extent.
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Affiliation(s)
- Guanzhong Mao
- Department of Cell and Molecular Biology, Biomedical Centre, Uppsala, Sweden
| | - Abhishek S. Srivastava
- Department of Cell and Molecular Biology, Biomedical Centre, Uppsala, Sweden
- Discovery Sciences, AstraZeneca R&D, Cambridge Science Park, Cambridge, United Kingdom
| | - Shiying Wu
- Department of Cell and Molecular Biology, Biomedical Centre, Uppsala, Sweden
| | - David Kosek
- Department of Cell and Molecular Biology, Biomedical Centre, Uppsala, Sweden
| | - Magnus Lindell
- Department of Cell and Molecular Biology, Biomedical Centre, Uppsala, Sweden
| | - Leif A. Kirsebom
- Department of Cell and Molecular Biology, Biomedical Centre, Uppsala, Sweden
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11
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Liu X, Chen Y, Fierke CA. Inner-Sphere Coordination of Divalent Metal Ion with Nucleobase in Catalytic RNA. J Am Chem Soc 2017; 139:17457-17463. [PMID: 29116782 PMCID: PMC6020041 DOI: 10.1021/jacs.7b08755] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Identification of the function of metal ions and the RNA moieties, particularly nucleobases, that bind metal ions is important in RNA catalysis. Here we combine single-atom and abasic substitutions to probe functions of conserved nucleobases in ribonuclease P (RNase P). Structural and biophysical studies of bacterial RNase P propose direct coordination of metal ions by the nucleobases of conserved uridine and guanosine in helix P4 of the RNA subunit (P RNA). To biochemically probe the function of metal ion interactions, we substituted the universally conserved bulged uridine (U51) in the P4 helix of circularly permuted Bacillus subtilis P RNA with 4-thiouridine, 4-deoxyuridine, and abasic modifications and G378/379 with 2-aminopurine, N7-deazaguanosine, and 6-thioguanosine. The functional group modifications of U51 decrease RNase P-catalyzed phosphodiester bond cleavage 16- to 23-fold, as measured by the single-turnover cleavage rate constant. The activity of the 4-thiouridine RNase P is partially rescued by addition of Cd(II) or Mn(II) ions. This is the first time a metal-rescue experiment provides evidence for inner-sphere divalent metal ion coordination with a nucleobase. Modifications of G379 modestly decrease the cleavage activity of RNase P, suggesting outer-sphere coordination of O6 on G379 to a metal ion. These data provide biochemical evidence for catalytically important interactions of the P4 helix of P RNA with metal ions, demonstrating that the bulged uridine coordinates at least one catalytic metal ion through an inner-sphere interaction. The combination of single-atom and abasic nucleotide substitutions provides a powerful strategy to probe functions of conserved nucleobases in large RNAs.
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Affiliation(s)
- Xin Liu
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Yu Chen
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Carol A. Fierke
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
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12
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Mechanistic Insights Into Catalytic RNA-Protein Complexes Involved in Translation of the Genetic Code. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2017. [PMID: 28683922 DOI: 10.1016/bs.apcsb.2017.04.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/28/2023]
Abstract
The contemporary world is an "RNA-protein world" rather than a "protein world" and tracing its evolutionary origins is of great interest and importance. The different RNAs that function in close collaboration with proteins are involved in several key physiological processes, including catalysis. Ribosome-the complex megadalton cellular machinery that translates genetic information encoded in nucleotide sequence to amino acid sequence-epitomizes such an association between RNA and protein. RNAs that can catalyze biochemical reactions are known as ribozymes. They usually employ general acid-base catalytic mechanism, often involving the 2'-OH of RNA that activates and/or stabilizes a nucleophile during the reaction pathway. The protein component of such RNA-protein complexes (RNPCs) mostly serves as a scaffold which provides an environment conducive for the RNA to function, or as a mediator for other interacting partners. In this review, we describe those RNPCs that are involved at different stages of protein biosynthesis and in which RNA performs the catalytic function; the focus of the account is on highlighting mechanistic aspects of these complexes. We also provide a perspective on such associations in the context of proofreading during translation of the genetic code. The latter aspect is not much appreciated and recent works suggest that this is an avenue worth exploring, since an understanding of the subject can provide useful insights into how RNAs collaborate with proteins to ensure fidelity during these essential cellular processes. It may also aid in comprehending evolutionary aspects of such associations.
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13
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Martin WJ, Reiter NJ. Structural Roles of Noncoding RNAs in the Heart of Enzymatic Complexes. Biochemistry 2016; 56:3-13. [PMID: 27935277 DOI: 10.1021/acs.biochem.6b01106] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Over billions of years of evolution, nature has embraced proteins as the major workhorse molecules of the cell. However, nearly every aspect of metabolism is dependent upon how structured RNAs interact with proteins, ligands, and other nucleic acids. Key processes, including telomere maintenance, RNA processing, and protein synthesis, require large RNAs that assemble into elaborate three-dimensional shapes. These RNAs can (i) act as flexible scaffolds for protein subunits, (ii) participate directly in substrate recognition, and (iii) serve as catalytic components. Here, we juxtapose the near atomic level interactions of three ribonucleoprotein complexes: ribonuclease P (involved in 5' pre-tRNA processing), the spliceosome (responsible for pre-mRNA splicing), and telomerase (an RNA-directed DNA polymerase that extends the ends of chromosomes). The focus of this perspective is profiling the structural and dynamic roles of RNAs at the core of these enzymes, highlighting how large RNAs contribute to molecular recognition and catalysis.
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Affiliation(s)
- William J Martin
- Department of Biochemistry, Vanderbilt University , Nashville, Tennessee 37232, United States
| | - Nicholas J Reiter
- Department of Biochemistry, Vanderbilt University , Nashville, Tennessee 37232, United States
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14
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Klemm BP, Wu N, Chen Y, Liu X, Kaitany KJ, Howard MJ, Fierke CA. The Diversity of Ribonuclease P: Protein and RNA Catalysts with Analogous Biological Functions. Biomolecules 2016; 6:biom6020027. [PMID: 27187488 PMCID: PMC4919922 DOI: 10.3390/biom6020027] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 05/04/2016] [Accepted: 05/06/2016] [Indexed: 12/30/2022] Open
Abstract
Ribonuclease P (RNase P) is an essential endonuclease responsible for catalyzing 5' end maturation in precursor transfer RNAs. Since its discovery in the 1970s, RNase P enzymes have been identified and studied throughout the three domains of life. Interestingly, RNase P is either RNA-based, with a catalytic RNA subunit, or a protein-only (PRORP) enzyme with differential evolutionary distribution. The available structural data, including the active site data, provides insight into catalysis and substrate recognition. The hydrolytic and kinetic mechanisms of the two forms of RNase P enzymes are similar, yet features unique to the RNA-based and PRORP enzymes are consistent with different evolutionary origins. The various RNase P enzymes, in addition to their primary role in tRNA 5' maturation, catalyze cleavage of a variety of alternative substrates, indicating a diversification of RNase P function in vivo. The review concludes with a discussion of recent advances and interesting research directions in the field.
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Affiliation(s)
- Bradley P Klemm
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Nancy Wu
- Program in Chemical Biology, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Yu Chen
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48103, USA.
| | - Xin Liu
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48103, USA.
| | - Kipchumba J Kaitany
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Michael J Howard
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Carol A Fierke
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
- Program in Chemical Biology, University of Michigan, Ann Arbor, MI 48109, USA.
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48103, USA.
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15
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Abstract
Ribonuclease P (RNase P) is one of the first ribozymes discovered and it is found in all phylogenetic groups. It is responsible for processing the 5' end of pre-tRNAs as well as other RNA molecules. RNase P is formed by an RNA molecule responsible for catalysis and one or more proteins. Structural studies of the proteins from different organisms, the bacterial RNA component, and a bacterial RNase P holoenzyme/tRNA complex provide insights into the mechanism of this universal ribozyme. Together with the existing wealth of biochemical information, these studies provide atomic-level information on the mechanism of RNase P and continue to expand our understanding of the structure and architecture of large RNA molecules and ribonucleoprotein complexes, the nature of catalysis by ribozymes, the structural basis of recognition of RNA by RNA molecules, and the evolution of enzymes from the prebiotic, RNA-based world to the modern world.
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Affiliation(s)
- Alfonso Mondragón
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208, USA.
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16
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Reiter NJ, Osterman AK, Mondragón A. The bacterial ribonuclease P holoenzyme requires specific, conserved residues for efficient catalysis and substrate positioning. Nucleic Acids Res 2012; 40:10384-93. [PMID: 22904083 PMCID: PMC3488217 DOI: 10.1093/nar/gks744] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
RNase P is an RNA-based enzyme primarily responsible for 5′-end pre-tRNA processing. A structure of the bacterial RNase P holoenzyme in complex with tRNAPhe revealed the structural basis for substrate recognition, identified the active site location, and showed how the protein component increases functionality. The active site includes at least two metal ions, a universal uridine (U52), and P RNA backbone moieties, but it is unclear whether an adjacent, bacterially conserved protein loop (residues 52–57) participates in catalysis. Here, mutagenesis combined with single-turnover reaction kinetics demonstrate that point mutations in this loop have either no or modest effects on catalytic efficiency. Similarly, amino acid changes in the ‘RNR’ region, which represent the most conserved region of bacterial RNase P proteins, exhibit negligible changes in catalytic efficiency. However, U52 and two bacterially conserved protein residues (F17 and R89) are essential for efficient Thermotoga maritima RNase P activity. The U52 nucleotide binds a metal ion at the active site, whereas F17 and R89 are positioned >20 Å from the cleavage site, probably making contacts with N−4 and N−5 nucleotides of the pre-tRNA 5′-leader. This suggests a synergistic coupling between transition state formation and substrate positioning via interactions with the leader.
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Affiliation(s)
- Nicholas J Reiter
- Department of Molecular Biosciences, Northwestern University, 2205 Tech Dr., Evanston, IL 60208, USA.
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17
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Kazantsev AV, Rambo RP, Karimpour S, Santalucia J, Tainer JA, Pace NR. Solution structure of RNase P RNA. RNA (NEW YORK, N.Y.) 2011; 17:1159-71. [PMID: 21531920 PMCID: PMC3096047 DOI: 10.1261/rna.2563511] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Accepted: 03/30/2011] [Indexed: 05/25/2023]
Abstract
The ribonucleoprotein enzyme ribonuclease P (RNase P) processes tRNAs by cleavage of precursor-tRNAs. RNase P is a ribozyme: The RNA component catalyzes tRNA maturation in vitro without proteins. Remarkable features of RNase P include multiple turnovers in vivo and ability to process diverse substrates. Structures of the bacterial RNase P, including full-length RNAs and a ternary complex with substrate, have been determined by X-ray crystallography. However, crystal structures of free RNA are significantly different from the ternary complex, and the solution structure of the RNA is unknown. Here, we report solution structures of three phylogenetically distinct bacterial RNase P RNAs from Escherichia coli, Agrobacterium tumefaciens, and Bacillus stearothermophilus, determined using small angle X-ray scattering (SAXS) and selective 2'-hydroxyl acylation analyzed by primer extension (SHAPE) analysis. A combination of homology modeling, normal mode analysis, and molecular dynamics was used to refine the structural models against the empirical data of these RNAs in solution under the high ionic strength required for catalytic activity.
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Affiliation(s)
- Alexei V Kazantsev
- Department of MCD Biology, University of Colorado, Boulder, Colorado 80309, USA
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18
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Reiter NJ, Osterman A, Torres-Larios A, Swinger KK, Pan T, Mondragón A. Structure of a bacterial ribonuclease P holoenzyme in complex with tRNA. Nature 2010; 468:784-9. [PMID: 21076397 PMCID: PMC3058908 DOI: 10.1038/nature09516] [Citation(s) in RCA: 237] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Accepted: 09/17/2010] [Indexed: 01/22/2023]
Abstract
Ribonuclease (RNase) P is the universal ribozyme responsible for 5'-end tRNA processing. We report the crystal structure of the Thermotoga maritima RNase P holoenzyme in complex with tRNA(Phe). The 154 kDa complex consists of a large catalytic RNA (P RNA), a small protein cofactor and a mature tRNA. The structure shows that RNA-RNA recognition occurs through shape complementarity, specific intermolecular contacts and base-pairing interactions. Soaks with a pre-tRNA 5' leader sequence with and without metal help to identify the 5' substrate path and potential catalytic metal ions. The protein binds on top of a universally conserved structural module in P RNA and interacts with the leader, but not with the mature tRNA. The active site is composed of phosphate backbone moieties, a universally conserved uridine nucleobase, and at least two catalytically important metal ions. The active site structure and conserved RNase P-tRNA contacts suggest a universal mechanism of catalysis by RNase P.
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Affiliation(s)
- Nicholas J Reiter
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208, USA
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19
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Abstract
Nuclear ribonuclease (RNase) P is a ubiquitous essential ribonucleoprotein complex, one of only two known RNA-based enzymes found in all three domains of life. The RNA component is the catalytic moiety of RNases P across all phylogenetic domains; it contains a well-conserved core, whereas peripheral structural elements are diverse. RNA components of eukaryotic RNases P tend to be less complex than their bacterial counterparts, a simplification that is accompanied by a dramatic reduction of their catalytic ability in the absence of protein. The size and complexity of the protein moieties increase dramatically from bacterial to archaeal to eukaryotic enzymes, apparently reflecting the delegation of some structural functions from RNA to proteins and, perhaps, in response to the increased complexity of the cellular environment in the more evolutionarily advanced organisms; the reasons for the increased dependence on proteins are not clear. We review current information on RNase P and the closely related universal eukaryotic enzyme RNase MRP, focusing on their functions and structural organization.
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Affiliation(s)
- Olga Esakova
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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20
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Hsieh J, Koutmou KS, Rueda D, Koutmos M, Walter NG, Fierke CA. A divalent cation stabilizes the active conformation of the B. subtilis RNase P x pre-tRNA complex: a role for an inner-sphere metal ion in RNase P. J Mol Biol 2010; 400:38-51. [PMID: 20434461 PMCID: PMC2939038 DOI: 10.1016/j.jmb.2010.04.050] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 04/22/2010] [Accepted: 04/24/2010] [Indexed: 01/25/2023]
Abstract
Metal ions interact with RNA to enhance folding, stabilize structure, and, in some cases, facilitate catalysis. Assigning functional roles to specifically bound metal ions presents a major challenge in analyzing the catalytic mechanisms of ribozymes. Bacillus subtilis ribonuclease P (RNase P), composed of a catalytically active RNA subunit (PRNA) and a small protein subunit (P protein), catalyzes the 5'-end maturation of precursor tRNAs (pre-tRNAs). Inner-sphere coordination of divalent metal ions to PRNA is essential for catalytic activity but not for the formation of the RNase P x pre-tRNA (enzyme-substrate, ES) complex. Previous studies have demonstrated that this ES complex undergoes an essential conformational change (to the ES* conformer) before the cleavage step. Here, we show that the ES* conformer is stabilized by a high-affinity divalent cation capable of inner-sphere coordination, such as Ca(II) or Mg(II). Additionally, a second, lower-affinity Mg(II) activates cleavage catalyzed by RNase P. Structural changes that occur upon binding Ca(II) to the ES complex were determined by time-resolved Förster resonance energy transfer measurements of the distances between donor-acceptor fluorophores introduced at specific locations on the P protein and pre-tRNA 5' leader. These data demonstrate that the 5' leader of pre-tRNA moves 4 to 6 A closer to the PRNA x P protein interface during the ES-to-ES* transition and suggest that the metal-dependent conformational change reorganizes the bound substrate in the active site to form a catalytically competent ES* complex.
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Affiliation(s)
- John Hsieh
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan
| | | | - David Rueda
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan
| | - Markos Koutmos
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan
| | - Nils G. Walter
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan
| | - Carol A. Fierke
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan
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21
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Koutmou KS, Casiano-Negroni A, Getz MM, Pazicni S, Andrews AJ, Penner-Hahn JE, Al-Hashimi HM, Fierke CA. NMR and XAS reveal an inner-sphere metal binding site in the P4 helix of the metallo-ribozyme ribonuclease P. Proc Natl Acad Sci U S A 2010; 107:2479-84. [PMID: 20133747 PMCID: PMC2823894 DOI: 10.1073/pnas.0906319107] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Functionally critical metals interact with RNA through complex coordination schemes that are currently difficult to visualize at the atomic level under solution conditions. Here, we report a new approach that combines NMR and XAS to resolve and characterize metal binding in the most highly conserved P4 helix of ribonuclease P (RNase P), the ribonucleoprotein that catalyzes the divalent metal ion-dependent maturation of the 5' end of precursor tRNA. Extended X-ray absorption fine structure (EXAFS) spectroscopy reveals that the Zn(2+) bound to a P4 helix mimic is six-coordinate, with an average Zn-O/N bond distance of 2.08 A. The EXAFS data also show intense outer-shell scattering indicating that the zinc ion has inner-shell interactions with one or more RNA ligands. NMR Mn(2+) paramagnetic line broadening experiments reveal strong metal localization at residues corresponding to G378 and G379 in B. subtilis RNase P. A new "metal cocktail" chemical shift perturbation strategy involving titrations with , Zn(2+), and confirm an inner-sphere metal interaction with residues G378 and G379. These studies present a unique picture of how metals coordinate to the putative RNase P active site in solution, and shed light on the environment of an essential metal ion in RNase P. Our experimental approach presents a general method for identifying and characterizing inner-sphere metal ion binding sites in RNA in solution.
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22
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McClain WH, Lai LB, Gopalan V. Trials, travails and triumphs: an account of RNA catalysis in RNase P. J Mol Biol 2010; 397:627-46. [PMID: 20100492 DOI: 10.1016/j.jmb.2010.01.038] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2009] [Revised: 01/12/2010] [Accepted: 01/19/2010] [Indexed: 12/16/2022]
Abstract
Last December marked the 20th anniversary of the Nobel Prize in Chemistry to Sidney Altman and Thomas Cech for their discovery of RNA catalysts in bacterial ribonuclease P (an enzyme catalyzing 5' maturation of tRNAs) and a self-splicing rRNA of Tetrahymena, respectively. Coinciding with the publication of a treatise on RNase P, this review provides a historical narrative, a brief report on our current knowledge, and a discussion of some research prospects on RNase P.
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Affiliation(s)
- William H McClain
- Department of Bacteriology, College of Agriculture & Life Sciences, University of Wisconsin, Madison, WI 53706, USA.
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23
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Lai LB, Vioque A, Kirsebom LA, Gopalan V. Unexpected diversity of RNase P, an ancient tRNA processing enzyme: challenges and prospects. FEBS Lett 2009; 584:287-96. [PMID: 19931535 DOI: 10.1016/j.febslet.2009.11.048] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2009] [Revised: 11/09/2009] [Accepted: 11/13/2009] [Indexed: 12/16/2022]
Abstract
For an enzyme functioning predominantly in a seemingly housekeeping role of 5' tRNA maturation, RNase P displays a remarkable diversity in subunit make-up across the three domains of life. Despite the protein complexity of this ribonucleoprotein enzyme increasing dramatically from bacteria to eukarya, the catalytic function rests with the RNA subunit during evolution. However, the recent demonstration of a protein-only human mitochondrial RNase P has added further intrigue to the compositional variability of this enzyme. In this review, we discuss some possible reasons underlying the structural diversity of the active sites, and use them as thematic bases for elaborating new directions to understand how functional variations might have contributed to the complex evolution of RNase P.
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Affiliation(s)
- Lien B Lai
- Department of Biochemistry and Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
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24
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Frederiksen JK, Piccirilli JA. Separation of RNA phosphorothioate oligonucleotides by HPLC. Methods Enzymol 2009; 468:289-309. [PMID: 20946775 DOI: 10.1016/s0076-6879(09)68014-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Phosphorothioate oligonucleotides are indispensable tools for probing nucleic acid structure and function and for the design of antisense therapeutics. Many applications involving phosphorothioates require site- and stereospecific substitution of individual pro-R(P) or pro-S(P) nonbridging oxygens. However, the traditional approach to phosphorothioate synthesis produces a mixture of R(P) and S(P) diastereomers that must be separated prior to use. High-performance liquid chromatography (HPLC) has proven to be a versatile method for effecting this separation, with both reversed phase (RP) and strong anion exchange (SAX) protocols yielding favorable results. In this chapter, we present several examples of successful separations of RNA phosphorothioate diastereomers by HPLC. We also report the use of complementary DNA oligonucleotides for the separation of poorly resolved phosphorothioate RNAs.
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Affiliation(s)
- John K Frederiksen
- The Pritzker School of Medicine, University of Chicago, Chicago, Illinois, USA
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25
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Binding of C5 protein to P RNA enhances the rate constant for catalysis for P RNA processing of pre-tRNAs lacking a consensus (+ 1)/C(+ 72) pair. J Mol Biol 2009; 395:1019-37. [PMID: 19917291 DOI: 10.1016/j.jmb.2009.11.027] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2009] [Revised: 11/03/2009] [Accepted: 11/10/2009] [Indexed: 12/23/2022]
Abstract
The RNA subunit of the ribonucleoprotein enzyme ribonuclease P (RNase P (P RNA) contains the active site, but binding of Escherichia coli RNase P protein (C5) to P RNA increases the rate constant for catalysis for certain pre-tRNA substrates up to 1000-fold. Structure-swapping experiments between a substrate that is cleaved slowly by P RNA alone (pre-tRNA(f-met605)) and one that is cleaved quickly (pre-tRNA(met608)) pinpoint the characteristic C(+1)/A(+72) base pair of initiator tRNA(f-met) as the sole determinant of slow RNA-alone catalysis. Unlike other substrate modifications that slow RNA-alone catalysis, the presence of a C(+1)/A(+72) base pair reduces the rate constant for processing at both correct and miscleavage sites, indicating an indirect but nonetheless important role in catalysis. Analysis of the Mg(2)(+) dependence of apparent catalytic rate constants for pre-tRNA(met608) and a pre-tRNA(met608) (+1)C/(+72)A mutant provides evidence that C5 promotes rate enhancement primarily by compensating for the decrease in the affinity of metal ions important for catalysis engendered by the presence of the CA pair. Together, these results support and extend current models for RNase P substrate recognition in which contacts involving the conserved (+1)G/C(+72) pair of tRNA stabilize functional metal ion binding. Additionally, these observations suggest that C5 protein has evolved to compensate for tRNA variation at positions important for binding to P RNA, allowing for tRNA specialization.
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26
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Frederiksen JK, Piccirilli JA. Identification of catalytic metal ion ligands in ribozymes. Methods 2009; 49:148-66. [PMID: 19651216 DOI: 10.1016/j.ymeth.2009.07.005] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2009] [Revised: 07/20/2009] [Accepted: 07/29/2009] [Indexed: 01/05/2023] Open
Abstract
Site-bound metal ions participate in the catalytic mechanisms of many ribozymes. Understanding these mechanisms therefore requires knowledge of the specific ligands on both substrate and ribozyme that coordinate these catalytic metal ions. A number of different structural and biochemical strategies have been developed and refined for identifying metal ion binding sites within ribozymes, and for assessing the catalytic contributions of the metal ions bound at those sites. We review these approaches and provide examples of their application, focusing in particular on metal ion rescue experiments and their roles in the construction of the transition state models for the Tetrahymena group I and RNase P ribozymes.
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Affiliation(s)
- John K Frederiksen
- The Pritzker School of Medicine, The University of Chicago, Chicago, IL 60637, USA
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27
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28
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Hartmann RK, Gössringer M, Späth B, Fischer S, Marchfelder A. The making of tRNAs and more - RNase P and tRNase Z. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2009; 85:319-68. [PMID: 19215776 DOI: 10.1016/s0079-6603(08)00808-8] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Transfer-RNA (tRNA) molecules are essential players in protein biosynthesis. They are transcribed as precursors, which have to be extensively processed at both ends to become functional adaptors in protein synthesis. Two endonucleases that directly interact with the tRNA moiety, RNase P and tRNase Z, remove extraneous nucleotides on the molecule's 5'- and 3'-side, respectively. The ribonucleoprotein enzyme RNase P was identified almost 40 years ago and is considered a vestige from the "RNA world". Here, we present the state of affairs on prokaryotic RNase P, with a focus on recent findings on its role in RNA metabolism. tRNase Z was only identified 6 years ago, and we do not yet have a comprehensive understanding of its function. The current knowledge on prokaryotic tRNase Z in tRNA 3'-processing is reviewed here. A second, tRNase Z-independent pathway of tRNA 3'-end maturation involving 3'-exonucleases will also be discussed.
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Affiliation(s)
- Roland K Hartmann
- Philipps-Universität Marburg, Institut für Pharmazeutische Chemie, Marbacher Weg 6, D-35037 Marburg, Germany
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29
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Berchanski A, Lapidot A. Bacterial RNase P RNA is a drug target for aminoglycoside-arginine conjugates. Bioconjug Chem 2008; 19:1896-906. [PMID: 18712898 DOI: 10.1021/bc800191u] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The ribonuclease P (RNase P) holoenzymes are RNPs composed of RNase P RNA (PRNA) and a variable number of P protein subunits. Primary differences in structure and function between bacterial and eukaryotic RNase P and its indispensability for cell viability make the bacterial enzyme an attractive drug target. On the basis of our previous studies, aminoglycoside-arginine conjugates (AACs) bind to HIV-1 TAR and Rev responsive element (RRE) RNAs significantly more efficiently than neomycin B. Their specific inhibition of bacterial rRNA as well as the findings that the hexa-arginine neomycin derivative (NeoR6) is 500-fold more potent than neomycin B in inhibiting bacterial RNase P, led us to explore the structure-function relationships of AACs in comparison to a new set of aminoglycoside-polyarginine conjugates (APACs). We here present predicted binding modes of AACs and APACs to PRNA. We used a multistep docking approach comprising rigid docking full scans and final refinement of the obtained complexes. Our docking results suggest three possible mechanisms of RNase P inhibition by AACs and APACs: competition with the P protein and pre-tRNA on binding to P1-P4 multihelix junction and to J19/4 region (probably including displacement of Mg2+ ions from the P4 helix) of PRNA; competition with Mg2+ ions near the P15 loop; and competition with the P protein and/or pre-tRNA near the P15 helix and interfering with interactions between the P protein and pre-tRNA at this region. The APACs revealed about 10-fold lower intermolecular energy than AACs, indicating stronger interactions of APACs than AACs with PRNA.
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Affiliation(s)
- Alexander Berchanski
- Department of Organic Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
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Smith JK, Hsieh J, Fierke CA. Importance of RNA-protein interactions in bacterial ribonuclease P structure and catalysis. Biopolymers 2007; 87:329-38. [PMID: 17868095 DOI: 10.1002/bip.20846] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Ribonuclease P (RNase P) is a ribonucleoprotein (RNP) complex that catalyzes the metal-dependent maturation of the 5' end of precursor tRNAs (pre-tRNAs) in all organisms. RNase P is comprised of a catalytic RNA (P RNA), and at least one essential protein (P protein). Although P RNA is the catalytic subunit of the enzyme and is active in the absence of P protein under high salt concentrations in vitro, the protein is still required for enzyme activity in vivo. Therefore, the function of the P protein and how it interacts with both P RNA and pre-tRNA have been the focus of much ongoing research. RNA-protein interactions in RNase P serve a number of critical roles in the RNP including stabilizing the structure, and enhancing the affinity for substrates and metal ions. This review examines the role of RNA-protein interactions in bacterial RNase P from both structural and mechanistic perspectives.
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Affiliation(s)
- J Kristin Smith
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, MI 48109, USA
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31
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Brännvall M, Kikovska E, Wu S, Kirsebom LA. Evidence for Induced Fit in Bacterial RNase P RNA-mediated Cleavage. J Mol Biol 2007; 372:1149-64. [PMID: 17719605 DOI: 10.1016/j.jmb.2007.07.030] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2007] [Revised: 07/06/2007] [Accepted: 07/09/2007] [Indexed: 11/26/2022]
Abstract
RNase P with its catalytic RNA subunit is involved in the processing of a number of RNA precursors with different structures. However, precursor tRNAs are the most abundant substrates for RNase P. Available data suggest that a tRNA is folded into its characteristic structure already at the precursor state and that RNase P recognizes this structure. The tRNA D-/T-loop domain (TSL-region) is suggested to interact with the specificity domain of RNase P RNA while residues in the catalytic domain interact with the cleavage site. Here, we have studied the consequences of a productive interaction between the TSL-region and its binding site (TBS) in the specificity domain using tRNA precursors and various hairpin-loop model substrates. The different substrates were analyzed with respect to cleavage site recognition, ground-state binding, cleavage as a function of the concentration of Mg(2+) and the rate of cleavage under conditions where chemistry is suggested to be rate limiting using wild-type Escherichia coli RNase P RNA, M1 RNA, and M1 RNA variants with structural changes in the TBS-region. On the basis of our data, we conclude that a productive TSL/TBS interaction results in a conformational change in the M1 RNA substrate complex that has an effect on catalysis. Moreover, it is likely that this conformational change comprises positioning of chemical groups (and Mg(2+)) at and in the vicinity of the cleavage site. Hence, our findings are consistent with an induced-fit mechanism in RNase P RNA-mediated cleavage.
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Affiliation(s)
- Mathias Brännvall
- Department of Cell and Molecular Biology, Box 596, Biomedical Centre, SE-751 24 Uppsala, Sweden
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32
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Forconi M, Piccirilli JA, Herschlag D. Modulation of individual steps in group I intron catalysis by a peripheral metal ion. RNA (NEW YORK, N.Y.) 2007; 13:1656-67. [PMID: 17720880 PMCID: PMC1986806 DOI: 10.1261/rna.632007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Enzymes are complex macromolecules that catalyze chemical reactions at their active sites. Important information about catalytic interactions is commonly gathered by perturbation or mutation of active site residues that directly contact substrates. However, active sites are engaged in intricate networks of interactions within the overall structure of the macromolecule, and there is a growing body of evidence about the importance of peripheral interactions in the precise structural organization of the active site. Here, we use functional studies, in conjunction with published structural information, to determine the effect of perturbation of a peripheral metal ion binding site on catalysis in a well-characterized catalytic RNA, the Tetrahymena thermophila group I ribozyme. We perturbed the metal ion binding site by site-specifically introducing a phosphorothioate substitution in the ribozyme's backbone, replacing the native ligands (the pro-R (P) oxygen atoms at positions 307 and 308) with sulfur atoms. Our data reveal that these perturbations affect several reaction steps, including the chemical step, despite the absence of direct contacts of this metal ion with the atoms involved in the chemical transformation. As structural probing with hydroxyl radicals did not reveal significant change in the three-dimensional structure upon phosphorothioate substitution, the effects are likely transmitted through local, rather subtle conformational rearrangements. Addition of Cd(2+), a thiophilic metal ion, rescues some reaction steps but has deleterious effects on other steps. These results suggest that native interactions in the active site may have been aligned by the naturally occurring peripheral residues and interactions to optimize the overall catalytic cycle.
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Affiliation(s)
- Marcello Forconi
- Department of Biochemistry, Stanford University, Stanford, California 94305, USA
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33
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Sun L, Harris ME. Evidence that binding of C5 protein to P RNA enhances ribozyme catalysis by influencing active site metal ion affinity. RNA (NEW YORK, N.Y.) 2007; 13:1505-15. [PMID: 17652407 PMCID: PMC1950769 DOI: 10.1261/rna.571007] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The RNA subunit (P RNA) of the bacterial RNase P ribonucleoprotein is a ribozyme that catalyzes the Mg-dependent hydrolysis of pre-tRNA, but it requires an essential protein cofactor (P protein) in vivo that enhances substrate binding affinities and catalytic rates in a substrate dependent manner. Previous studies of Bacillus subtilis RNase P, containing a Type B RNA subunit, showed that its cognate protein subunit increases the affinity of metal ions important for catalysis, but the functional role of these ions is unknown. Here, we demonstrate that the Mg2+ dependence of the catalytic step for Escherichia coli RNase P, which contains a more common Type A RNA subunit, is also modulated by its cognate protein subunit (C5), indicating that this property is fundamental to P protein. To monitor specifically the binding of active site metal ions, we analyzed quantitatively the rescue by Cd2+ of an inhibitory Rp phosphorothioate modification at the pre-tRNA cleavage site. The results show that binding of C5 protein increases the apparent affinity of the rescuing Cd2+, providing evidence that C5 protein enhances metal ion affinity in the active site, and thus is likely to contribute significantly to rate enhancement at physiological metal ion concentrations.
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Affiliation(s)
- Lei Sun
- Center for RNA Molecular Biology, Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
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Willkomm DK, Hartmann RK. An important piece of the RNase P jigsaw solved. Trends Biochem Sci 2007; 32:247-50. [PMID: 17485211 DOI: 10.1016/j.tibs.2007.04.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Accepted: 04/30/2007] [Indexed: 11/21/2022]
Abstract
RNase P is the ribonucleoprotein enzyme that generates the mature 5' ends of tRNAs throughout all three kingdoms of life. Long known to function as a ribozyme in bacteria and several archaea, it has remained unclear if eukaryal RNase P has entirely lost this RNA-alone catalytic capacity (i.e. the ability to perform catalysis even if the protein part of the enzyme is removed). This controversial debate has now ended after the recent demonstration that eukaryal RNase P also exhibits ribozyme activity.
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Affiliation(s)
- Dagmar K Willkomm
- Institut für Pharmazeutische Chemie, Philipps-Universität Marburg, D-35037 Marburg, Germany
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Niranjanakumari S, Day-Storms JJ, Ahmed M, Hsieh J, Zahler NH, Venters RA, Fierke CA. Probing the architecture of the B. subtilis RNase P holoenzyme active site by cross-linking and affinity cleavage. RNA (NEW YORK, N.Y.) 2007; 13:521-35. [PMID: 17299131 PMCID: PMC1831860 DOI: 10.1261/rna.308707] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2006] [Accepted: 12/21/2006] [Indexed: 05/03/2023]
Abstract
Bacterial ribonuclease P (RNase P) is a ribonucleoprotein complex composed of one catalytic RNA (PRNA) and one protein subunit (P protein) that together catalyze the 5' maturation of precursor tRNA. High-resolution X-ray crystal structures of the individual P protein and PRNA components from several species have been determined, and structural models of the RNase P holoenzyme have been proposed. However, holoenzyme models have been limited by a lack of distance constraints between P protein and PRNA in the holoenzyme-substrate complex. Here, we report the results of extensive cross-linking and affinity cleavage experiments using single-cysteine P protein variants derivatized with either azidophenacyl bromide or 5-iodoacetamido-1,10-o-phenanthroline to determine distance constraints and to model the Bacillus subtilis holoenzyme-substrate complex. These data indicate that the evolutionarily conserved RNR motif of P protein is located near (<15 Angstroms) the pre-tRNA cleavage site, the base of the pre-tRNA acceptor stem and helix P4 of PRNA, the putative active site of the enzyme. In addition, the metal binding loop and N-terminal region of the P protein are proximal to the P3 stem-loop of PRNA. Studies using heterologous holoenzymes composed of covalently modified B. subtilis P protein and Escherichia coli M1 RNA indicate that P protein binds similarly to both RNAs. Together, these data indicate that P protein is positioned close to the RNase P active site and may play a role in organizing the RNase P active site.
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Getz MM, Andrews AJ, Fierke CA, Al-Hashimi HM. Structural plasticity and Mg2+ binding properties of RNase P P4 from combined analysis of NMR residual dipolar couplings and motionally decoupled spin relaxation. RNA (NEW YORK, N.Y.) 2007; 13:251-66. [PMID: 17194721 PMCID: PMC1781369 DOI: 10.1261/rna.264207] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The P4 helix is an essential element of ribonuclease P (RNase P) that is believed to bind catalytically important metals. Here, we applied a combination of NMR residual dipolar couplings (RDCs) and a recently introduced domain-elongation strategy for measuring "motionally decoupled" relaxation data to characterize the structural dynamics of the P4 helix from Bacillus subtilis RNase P. In the absence of divalent ions, the two P4 helical domains undergo small amplitude (approximately 13 degrees) collective motions about an average interhelical angle of 10 degrees. The highly conserved U7 bulge and helical residue C8, which are proposed to be important for substrate recognition and metal binding, are locally mobile at pico- to nanosecond timescales and together form the pivot point for the collective domain motions. Chemical shift mapping reveals significant association of Mg2+ ions at the P4 major groove near the flexible pivot point at residues (A5, G22, G23) previously identified to bind catalytically important metals. The Mg2+ ions do not, however, significantly alter the structure or dynamics of P4. Analysis of results in the context of available X-ray structures of the RNA component of RNase P and structural models that include the pre-tRNA substrate suggest that the internal motions observed in P4 likely facilitate adaptive changes in conformation that take place during folding and substrate recognition, possibly aided by interactions with Mg2+ ions. Our results add to a growing view supporting the existence of functionally important internal motions in RNA occurring at nanosecond timescales.
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Affiliation(s)
- Melissa M Getz
- Department of Chemistry, University of Michigan, Ann Arbor 48109, USA
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37
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Abstract
Ribonuclease P (RNase P) is a ubiquitous endonuclease that catalyses the maturation of the 5' end of transfer RNA (tRNA). Although it carries out a biochemically simple reaction, RNase P is a complex ribonucleoprotein particle composed of a single large RNA and at least one protein component. In bacteria and some archaea, the RNA component of RNase P can catalyse tRNA maturation in vitro in the absence of proteins. The discovery of the catalytic activity of the bacterial RNase P RNA triggered numerous mechanistic and biochemical studies of the reactions catalysed by the RNA alone and by the holoenzyme and, in recent years, structures of individual components of the RNase P holoenzyme have been determined. The goal of the present review is to summarize what is known about the bacterial RNase P, and to bring together the recent structural results with extensive earlier biochemical and phylogenetic findings.
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Affiliation(s)
- Alexei V Kazantsev
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, Colorado 80309-0347, USA
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