The Affinity of Magnesium Binding Sites in the Bacillus subtilis RNase P·Pre-tRNA Complex Is Enhanced by the Protein Subunit
Abstract
The RNA subunit of bacterial ribonuclease P (RNase P) requires high concentrations of magnesium ions for efficient catalysis of tRNA 5'-maturation in vitro. The protein component of RNase P, required for cleavage of precursor tRNA in vivo, enhances pre-tRNA binding by directly contacting the 5'-leader sequence. Using a combination of transient kinetics and equilibrium binding measurements, we now demonstrate that the protein component of RNase P also facilitates catalysis by specifically increasing the affinities of magnesium ions bound to the RNase P x pre-tRNA(Asp) complex. The protein component does not alter the number or apparent affinity of magnesium ions that are either diffusely associated with the RNase P RNA polyanion or required for binding mature tRNA(Asp). Nor does the protein component alter the pH dependence of pre-tRNA(Asp) cleavage catalyzed by RNase P, providing further evidence that the protein component does not directly stabilize the catalytic transition state. However, the protein subunit does increase the affinities of at least four magnesium sites that stabilize pre-tRNA binding and, possibly, catalysis. Furthermore, this stabilizing effect is coupled to the P protein/5'-leader contact in the RNase P holoenzyme x pre-tRNA complex. These results suggest that the protein component enhances the magnesium affinity of the RNase P x pre-tRNA complex indirectly by binding and positioning pre-tRNA. Furthermore, RNase P is inhibited by cobalt hexammine (K(I) =…
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
B. subtilis RNase P binds ~150 Mg2+ ions with an apparent affinity (K1/2) of 0.26 mM Mg at low K+ (~50 mM K+), decreasing to a K1/2 of ~1.5 mM Mg2+ with higher K+ (~150 mM K+).
“For example, B. subtilis RNase P binds ∼150 Mg2+ ions with an apparent affinity (K1/2) of 0.26 mM Mg at low K+ (∼50 mM K+), decreasing to a K1/2 of ∼1.5 mM Mg2+ with higher K+ (∼150 mM K+).76”
From Metals in Motion: Understanding Labile Metal Pools in Bacteria (2025) · cites this paper as [76]
Cited by
Sorted by citations
Metals in Motion: Understanding Labile Metal Pools in Bacteria
Helmann, J. D. (2025) · Biochemistry · doi:10.1021/acs.biochem.4c00726 · Cited by 49 · see citing works
- Authors
- Kurz, J. C., & Fierke, C. A.
- Affiliations
- University of Michigan (US)
- Corresponding author
- Fierke, Carol A.
- ORCID
- Fierke, Carol A.
- Venue
- Biochemistry
- Publisher
- American Chemical Society (ACS)
- Published
- 2002-07-01
- Volume
- 41
- Issue
- 30
- Pages
- 9545-9558
- ISSN
- 0006-2960 (ISSN-L)
- 1520-4995
- OpenAlex
- W2066304271
- Cited by
- 93
- References
- 0
- Citations by year
- 2026: 1 · 2025: 2 · 2024: 4 · 2023: 2 · 2022: 1 · 2021: 2 · 2020: 1 · 2019: 2 · 2018: 2 · 2017: 2 · 2016: 4 · 2015: 2 · 2014: 2 · 2013: 3 · 2012: 1
- FWCI
- 1.95
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- Biochemistry (publishedVersion)
- PubMed (publishedVersion)
- Funders
- National Institute of General Medical Sciences (R01GM055387, T32GM008487, GM-55387, GM08487)
- Topics
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › RNA and protein synthesis mechanisms
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Bacterial Genetics and Biotechnology
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › RNA modifications and cancer
- Keywords
- ribonuclease P, pre-tRNA, magnesium binding sites, metal ion catalysis, 5' leader sequence, Bacillus subtilis, catalytic mechanism
- MeSH terms
- Bacillus subtilis, Binding Sites, Catalysis, Cobalt, Hydrogen-Ion Concentration, Kinetics, Magnesium, Ribonucleases, RNA Precursors, RNA, Transfer, Asp
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
