1
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Modopathies Caused by Mutations in Genes Encoding for Mitochondrial RNA Modifying Enzymes: Molecular Mechanisms and Yeast Disease Models. Int J Mol Sci 2023; 24:ijms24032178. [PMID: 36768505 PMCID: PMC9917222 DOI: 10.3390/ijms24032178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 01/17/2023] [Accepted: 01/20/2023] [Indexed: 01/25/2023] Open
Abstract
In eukaryotes, mitochondrial RNAs (mt-tRNAs and mt-rRNAs) are subject to specific nucleotide modifications, which are critical for distinct functions linked to the synthesis of mitochondrial proteins encoded by mitochondrial genes, and thus for oxidative phosphorylation. In recent years, mutations in genes encoding for mt-RNAs modifying enzymes have been identified as being causative of primary mitochondrial diseases, which have been called modopathies. These latter pathologies can be caused by mutations in genes involved in the modification either of tRNAs or of rRNAs, resulting in the absence of/decrease in a specific nucleotide modification and thus on the impairment of the efficiency or the accuracy of the mitochondrial protein synthesis. Most of these mutations are sporadic or private, thus it is fundamental that their pathogenicity is confirmed through the use of a model system. This review will focus on the activity of genes that, when mutated, are associated with modopathies, on the molecular mechanisms through which the enzymes introduce the nucleotide modifications, on the pathological phenotypes associated with mutations in these genes and on the contribution of the yeast Saccharomyces cerevisiae to confirming the pathogenicity of novel mutations and, in some cases, for defining the molecular defects.
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2
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Deciphering the Role of Residues Involved in Disorder-To-Order Transition Regions in Archaeal tRNA Methyltransferase 5. Genes (Basel) 2021; 12:genes12030399. [PMID: 33799704 PMCID: PMC8000304 DOI: 10.3390/genes12030399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 03/01/2021] [Accepted: 03/08/2021] [Indexed: 11/16/2022] Open
Abstract
tRNA methyltransferase 5 (Trm5) enzyme is an S-adenosyl methionine (AdoMet)-dependent methyltransferase which methylates the G37 nucleotide at the N1 atom of the tRNA. The free form of Trm5 enzyme has three intrinsically disordered regions, which are highly flexible and lack stable three-dimensional structures. These regions gain ordered structures upon the complex formation with tRNA, also called disorder-to-order transition (DOT) regions. In this study, we performed molecular dynamics (MD) simulations of archaeal Trm5 in free and complex forms and observed that the DOT residues are highly flexible in free proteins and become stable in complex structures. The energetic contributions show that DOT residues are important for stabilising the complex. The DOT1 and DOT2 are mainly observed to be important for stabilising the complex, while DOT3 is present near the active site to coordinate the interactions between methyl-donating ligands and G37 nucleotides. In addition, mutational studies on the Trm5 complex showed that the wild type is more stable than the G37A tRNA mutant complex. The loss of productive interactions upon G37A mutation drives the AdoMet ligand away from the 37th nucleotide, and Arg145 in DOT3 plays a crucial role in stabilising the ligand, as well as the G37 nucleotide, in the wild-type complex. Further, the overall energetic contribution calculated using MMPBSA corroborates that the wild-type complex has a better affinity between Trm5 and tRNA. Overall, our study reveals that targeting DOT regions for binding could improve the inhibition of Trm5.
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3
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Potential Target Site for Inhibitors in MLS B Antibiotic Resistance. Antibiotics (Basel) 2021; 10:antibiotics10030264. [PMID: 33807634 PMCID: PMC7998614 DOI: 10.3390/antibiotics10030264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 02/24/2021] [Accepted: 02/24/2021] [Indexed: 11/17/2022] Open
Abstract
Macrolide-lincosamide-streptogramin B antibiotic resistance occurs through the action of erythromycin ribosome methylation (Erm) family proteins, causing problems due to their prevalence and high minimal inhibitory concentration, and feasibilities have been sought to develop inhibitors. Erms exhibit high conservation next to the N-terminal end region (NTER) as in ErmS, 64SQNF67. Side chains of homologous S, Q and F in ErmC' are surface-exposed, located closely together and exhibit intrinsic flexibility; these residues form a motif X. In S64 mutations, S64G, S64A and S64C exhibited 71%, 21% and 20% activity compared to the wild-type, respectively, conferring cell resistance. However, mutants harboring larger side chains did not confer resistance and retain the methylation activity in vitro. All mutants of Q65, Q65N, Q65E, Q65R, and Q65H lost their methyl group transferring activity in vivo and in vitro. At position F67, a size reduction of side-chain (F67A) or a positive charge (F67H) greatly reduced the activity to about 4% whereas F67L with a small size reduction caused a moderate loss, more than half of the activity. The increased size by F67Y and F67W reduced the activity by about 75%. In addition to stabilization of the cofactor, these amino acids could interact with substrate RNA near the methylatable adenine presumably to be catalytically well oriented with the SAM (S-adenosyl-L-methionine). These amino acids together with the NTER beside them could serve as unique potential inhibitor development sites. This region constitutes a divergent element due to the NTER which has variable length and distinct amino acids context in each Erm. The NTER or part of it plays critical roles in selective recognition of substrate RNA by Erms and this presumed target site might assume distinct local structure by induced conformational change with binding to substrate RNA and SAM, and contribute to the specific recognition of substrate RNA.
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4
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Masuda I, Takase R, Matsubara R, Paulines MJ, Gamper H, Limbach PA, Hou YM. Selective terminal methylation of a tRNA wobble base. Nucleic Acids Res 2019; 46:e37. [PMID: 29361055 PMCID: PMC5909439 DOI: 10.1093/nar/gky013] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 01/09/2018] [Indexed: 12/14/2022] Open
Abstract
Active tRNAs are extensively post-transcriptionally modified, particularly at the wobble position 34 and the position 37 on the 3′-side of the anticodon. The 5-carboxy-methoxy modification of U34 (cmo5U34) is present in Gram-negative tRNAs for six amino acids (Ala, Ser, Pro, Thr, Leu and Val), four of which (Ala, Ser, Pro and Thr) have a terminal methyl group to form 5-methoxy-carbonyl-methoxy-uridine (mcmo5U34) for higher reading-frame accuracy. The molecular basis for the selective terminal methylation is not understood. Many cmo5U34-tRNAs are essential for growth and cannot be substituted for mutational analysis. We show here that, with a novel genetic approach, we have created and isolated mutants of Escherichia coli tRNAPro and tRNAVal for analysis of the selective terminal methylation. We show that substitution of G35 in the anticodon of tRNAPro inactivates the terminal methylation, whereas introduction of G35 to tRNAVal confers it, indicating that G35 is a major determinant for the selectivity. We also show that, in tRNAPro, the terminal methylation at U34 is dependent on the primary m1G methylation at position 37 but not vice versa, indicating a hierarchical ranking of modifications between positions 34 and 37. We suggest that this hierarchy provides a mechanism to ensure top performance of a tRNA inside of cells.
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Affiliation(s)
- Isao Masuda
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Ryuichi Takase
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Ryuma Matsubara
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Mellie June Paulines
- Rieveschl Laboratories for Mass Spectrometry, Department of Chemistry, PO Box 210172, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Howard Gamper
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Patrick A Limbach
- Rieveschl Laboratories for Mass Spectrometry, Department of Chemistry, PO Box 210172, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Ya-Ming Hou
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
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5
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Hou YM, Masuda I, Gamper H. Codon-Specific Translation by m 1G37 Methylation of tRNA. Front Genet 2019; 9:713. [PMID: 30687389 PMCID: PMC6335274 DOI: 10.3389/fgene.2018.00713] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 12/20/2018] [Indexed: 12/31/2022] Open
Abstract
Although the genetic code is degenerate, synonymous codons for the same amino acid are not translated equally. Codon-specific translation is important for controlling gene expression and determining the proteome of a cell. At the molecular level, codon-specific translation is regulated by post-transcriptional epigenetic modifications of tRNA primarily at the wobble position 34 and at position 37 on the 3'-side of the anticodon. Modifications at these positions determine the quality of codon-anticodon pairing and the speed of translation on the ribosome. Different modifications operate in distinct mechanisms of codon-specific translation, generating a diversity of regulation that is previously unanticipated. Here we summarize recent work that demonstrates codon-specific translation mediated by the m1G37 methylation of tRNA at CCC and CCU codons for proline, an amino acid that has unique features in translation.
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Affiliation(s)
- Ya-Ming Hou
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, United States
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6
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Hori H, Kawamura T, Awai T, Ochi A, Yamagami R, Tomikawa C, Hirata A. Transfer RNA Modification Enzymes from Thermophiles and Their Modified Nucleosides in tRNA. Microorganisms 2018; 6:E110. [PMID: 30347855 PMCID: PMC6313347 DOI: 10.3390/microorganisms6040110] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 10/17/2018] [Accepted: 10/17/2018] [Indexed: 12/11/2022] Open
Abstract
To date, numerous modified nucleosides in tRNA as well as tRNA modification enzymes have been identified not only in thermophiles but also in mesophiles. Because most modified nucleosides in tRNA from thermophiles are common to those in tRNA from mesophiles, they are considered to work essentially in steps of protein synthesis at high temperatures. At high temperatures, the structure of unmodified tRNA will be disrupted. Therefore, thermophiles must possess strategies to stabilize tRNA structures. To this end, several thermophile-specific modified nucleosides in tRNA have been identified. Other factors such as RNA-binding proteins and polyamines contribute to the stability of tRNA at high temperatures. Thermus thermophilus, which is an extreme-thermophilic eubacterium, can adapt its protein synthesis system in response to temperature changes via the network of modified nucleosides in tRNA and tRNA modification enzymes. Notably, tRNA modification enzymes from thermophiles are very stable. Therefore, they have been utilized for biochemical and structural studies. In the future, thermostable tRNA modification enzymes may be useful as biotechnology tools and may be utilized for medical science.
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Affiliation(s)
- Hiroyuki Hori
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan.
| | - Takuya Kawamura
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan.
| | - Takako Awai
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan.
| | - Anna Ochi
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan.
| | - Ryota Yamagami
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan.
| | - Chie Tomikawa
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan.
| | - Akira Hirata
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan.
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7
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Wang C, Jia Q, Zeng J, Chen R, Xie W. Structural insight into the methyltransfer mechanism of the bifunctional Trm5. SCIENCE ADVANCES 2017; 3:e1700195. [PMID: 29214216 PMCID: PMC5714064 DOI: 10.1126/sciadv.1700195] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 11/01/2017] [Indexed: 06/07/2023]
Abstract
The wyosine derivatives present at position 37 in transfer RNAs (tRNAs) are critical for reading frame maintenance. The methyltransferase Trm5a from Pyrococcus abyssi (PaTrm5a) plays a key role in this hypermodification process in generating m1G37 and imG2, two products of the wyosine biosynthetic pathway, through two methyl transfers to distinct substrates, but the mechanism is currently unknown. We report two cocrystal structures of PaTrm5a in complex with tRNAPhe and reveal the structural basis for substrate recognition, which was supported by in vitro activity assays. The crystal structures showed that the D1 domain of the enzyme undergoes large conformational changes upon the binding of tRNA. The deletion of this domain greatly reduces the affinity and activity of PaTrm5a toward its RNA substrate, indicating that the enzyme recognizes the overall shape of tRNA. Using the small-angle x-ray scattering technique and crystallographic analysis, we discovered that PaTrm5a adopts distinct open conformations before and after the binding of tRNA. Last, through structure comparison with its ortholog Methanococcus jannaschii Trm5b (MjTrm5b), we propose a reaction mechanism for the double methylation capability of this unique enzyme.
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Affiliation(s)
- Caiyan Wang
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, 135 West Xingang Rd., Guangzhou, Guangdong 510275, People’s Republic of China
- Center for Cellular and Structural biology, Sun Yat-Sen University, 132 East Circle Rd., University City, Guangzhou, Guangdong 510006, People’s Republic of China
| | - Qian Jia
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, 135 West Xingang Rd., Guangzhou, Guangdong 510275, People’s Republic of China
- Center for Cellular and Structural biology, Sun Yat-Sen University, 132 East Circle Rd., University City, Guangzhou, Guangdong 510006, People’s Republic of China
| | - Jianhua Zeng
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, 135 West Xingang Rd., Guangzhou, Guangdong 510275, People’s Republic of China
- Center for Cellular and Structural biology, Sun Yat-Sen University, 132 East Circle Rd., University City, Guangzhou, Guangdong 510006, People’s Republic of China
| | - Ran Chen
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, 135 West Xingang Rd., Guangzhou, Guangdong 510275, People’s Republic of China
- Center for Cellular and Structural biology, Sun Yat-Sen University, 132 East Circle Rd., University City, Guangzhou, Guangdong 510006, People’s Republic of China
| | - Wei Xie
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, 135 West Xingang Rd., Guangzhou, Guangdong 510275, People’s Republic of China
- Center for Cellular and Structural biology, Sun Yat-Sen University, 132 East Circle Rd., University City, Guangzhou, Guangdong 510006, People’s Republic of China
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8
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Hou YM, Matsubara R, Takase R, Masuda I, Sulkowska JI. TrmD: A Methyl Transferase for tRNA Methylation With m 1G37. Enzymes 2017; 41:89-115. [PMID: 28601227 DOI: 10.1016/bs.enz.2017.03.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
TrmD is an S-adenosyl methionine (AdoMet)-dependent methyl transferase that synthesizes the methylated m1G37 in tRNA. TrmD is specific to and essential for bacterial growth, and it is fundamentally distinct from its eukaryotic and archaeal counterpart Trm5. TrmD is unusual by using a topological protein knot to bind AdoMet. Despite its restricted mobility, the TrmD knot has complex dynamics necessary to transmit the signal of AdoMet binding to promote tRNA binding and methyl transfer. Mutations in the TrmD knot block this intramolecular signaling and decrease the synthesis of m1G37-tRNA, prompting ribosomes to +1-frameshifts and premature termination of protein synthesis. TrmD is unique among AdoMet-dependent methyl transferases in that it requires Mg2+ in the catalytic mechanism. This Mg2+ dependence is important for regulating Mg2+ transport to Salmonella for survival of the pathogen in the host cell. The strict conservation of TrmD among bacterial species suggests that a better characterization of its enzymology and biology will have a broad impact on our understanding of bacterial pathogenesis.
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Affiliation(s)
- Ya-Ming Hou
- Thomas Jefferson University, Philadelphia, PA, United States.
| | - Ryuma Matsubara
- Thomas Jefferson University, Philadelphia, PA, United States
| | - Ryuichi Takase
- Thomas Jefferson University, Philadelphia, PA, United States
| | - Isao Masuda
- Thomas Jefferson University, Philadelphia, PA, United States
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9
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Urbonavičius J, Rutkienė R, Lopato A, Tauraitė D, Stankevičiūtė J, Aučynaitė A, Kaliniene L, van Tilbeurgh H, Meškys R. Evolution of tRNAPhe:imG2 methyltransferases involved in the biosynthesis of wyosine derivatives in Archaea. RNA (NEW YORK, N.Y.) 2016; 22:1871-1883. [PMID: 27852927 PMCID: PMC5113207 DOI: 10.1261/rna.057059.116] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 09/19/2016] [Indexed: 06/06/2023]
Abstract
Tricyclic wyosine derivatives are found at position 37 of eukaryotic and archaeal tRNAPhe In Archaea, the intermediate imG-14 is targeted by three different enzymes that catalyze the formation of yW-86, imG, and imG2. We have suggested previously that a peculiar methyltransferase (aTrm5a/Taw22) likely catalyzes two distinct reactions: N1-methylation of guanosine to yield m1G; and C7-methylation of imG-14 to yield imG2. Here we show that the recombinant aTrm5a/Taw22-like enzymes from both Pyrococcus abyssi and Nanoarchaeum equitans indeed possess such dual specificity. We also show that substitutions of individual conservative amino acids of P. abyssi Taw22 (P260N, E173A, and R174A) have a differential effect on the formation of m1G/imG2, while replacement of R134, F165, E213, and P262 with alanine abolishes the formation of both derivatives of G37. We further demonstrate that aTrm5a-type enzyme SSO2439 from Sulfolobus solfataricus, which has no N1-methyltransferase activity, exhibits C7-methyltransferase activity, thereby producing imG2 from imG-14. We thus suggest renaming such aTrm5a methyltransferases as Taw21 to distinguish between monofunctional and bifunctional aTrm5a enzymes.
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Affiliation(s)
- Jaunius Urbonavičius
- Department of Molecular Microbiology and Biotechnology, Institute of Biochemistry, Vilnius University, Vilnius 10222, Lithuania
- Department of Chemistry and Bioengineering, Vilnius Gediminas Technical University, Vilnius 10223, Lithuania
| | - Rasa Rutkienė
- Department of Molecular Microbiology and Biotechnology, Institute of Biochemistry, Vilnius University, Vilnius 10222, Lithuania
| | - Anželika Lopato
- Department of Molecular Microbiology and Biotechnology, Institute of Biochemistry, Vilnius University, Vilnius 10222, Lithuania
- Department of Chemistry and Bioengineering, Vilnius Gediminas Technical University, Vilnius 10223, Lithuania
| | - Daiva Tauraitė
- Department of Molecular Microbiology and Biotechnology, Institute of Biochemistry, Vilnius University, Vilnius 10222, Lithuania
| | - Jonita Stankevičiūtė
- Department of Molecular Microbiology and Biotechnology, Institute of Biochemistry, Vilnius University, Vilnius 10222, Lithuania
| | - Agota Aučynaitė
- Department of Molecular Microbiology and Biotechnology, Institute of Biochemistry, Vilnius University, Vilnius 10222, Lithuania
| | - Laura Kaliniene
- Department of Molecular Microbiology and Biotechnology, Institute of Biochemistry, Vilnius University, Vilnius 10222, Lithuania
| | - Herman van Tilbeurgh
- Institut de Biologie Intégrative de la Cellule, I2BC, CNRS Université Paris-Sud UMR9198, Orsay, France
| | - Rolandas Meškys
- Department of Molecular Microbiology and Biotechnology, Institute of Biochemistry, Vilnius University, Vilnius 10222, Lithuania
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10
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Christian T, Sakaguchi R, Perlinska AP, Lahoud G, Ito T, Taylor EA, Yokoyama S, Sulkowska JI, Hou YM. Methyl transfer by substrate signaling from a knotted protein fold. Nat Struct Mol Biol 2016; 23:941-948. [PMID: 27571175 PMCID: PMC5429141 DOI: 10.1038/nsmb.3282] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 07/27/2016] [Indexed: 12/13/2022]
Abstract
Proteins with knotted configurations, in comparison with unknotted proteins, are restricted in conformational space. Little is known regarding whether knotted proteins have sufficient dynamics to communicate between spatially separated substrate-binding sites. TrmD is a bacterial methyltransferase that uses a knotted protein fold to catalyze methyl transfer from S-adenosyl methionine (AdoMet) to G37-tRNA. The product, m1G37-tRNA, is essential for life and maintains protein-synthesis reading frames. Using an integrated approach of structural, kinetic, and computational analysis, we show that the structurally constrained TrmD knot is required for its catalytic activity. Unexpectedly, the TrmD knot undergoes complex internal movements that respond to AdoMet binding and signaling. Most of the signaling propagates the free energy of AdoMet binding, thereby stabilizing tRNA binding and allowing assembly of the active site. This work demonstrates new principles of knots as organized structures that capture the free energies of substrate binding and facilitate catalysis.
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Affiliation(s)
- Thomas Christian
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Reiko Sakaguchi
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Agata P Perlinska
- Center of New Technologies, University of Warsaw, Warsaw, Poland
- Inter-Faculty Individual Studies in Mathematics and Natural Sciences, University of Warsaw, Warsaw, Poland
| | - Georges Lahoud
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Takuhiro Ito
- RIKEN Systems and Structural Biology Center, Yokohama, Japan
- Graduate School of Science, University of Tokyo, Tokyo, Japan
- RIKEN Center for Life Science Technologies, Yokohama, Japan
| | - Erika A Taylor
- Department of Chemistry, Wesleyan University, Middletown, Connecticut, USA
| | - Shigeyuki Yokoyama
- RIKEN Systems and Structural Biology Center, Yokohama, Japan
- Graduate School of Science, University of Tokyo, Tokyo, Japan
- RIKEN Structural Biology Laboratory, Yokohama, Japan
| | - Joanna I Sulkowska
- Center of New Technologies, University of Warsaw, Warsaw, Poland
- Department of Chemistry, University of Warsaw, Warsaw, Poland
| | - Ya-Ming Hou
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
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11
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Wang C, Jia Q, Chen R, Wei Y, Li J, Ma J, Xie W. Crystal structures of the bifunctional tRNA methyltransferase Trm5a. Sci Rep 2016; 6:33553. [PMID: 27629654 PMCID: PMC5024318 DOI: 10.1038/srep33553] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 08/24/2016] [Indexed: 01/07/2023] Open
Abstract
tRNA methyltransferase Trm5 catalyses the transfer of a methyl group from S-adenosyl-L-methionine to G37 in eukaryotes and archaea. The N1-methylated guanosine is the product of the initial step of the wyosine hypermodification, which is essential for the maintenance of the reading frame during translation. As a unique member of this enzyme family, Trm5a from Pyrococcus abyssi (PaTrm5a) catalyses not only the methylation of N1, but also the further methylation of C7 on 4-demethylwyosine at position 37 to produce isowyosine, but the mechanism for the double methylation is poorly understood. Here we report four crystal structures of PaTrm5a ranging from 1.7- to 2.3-Å, in the apo form or in complex with various SAM analogues. These structures reveal that Asp243 specifically recognises the base moiety of SAM at the active site. Interestingly, the protein in our structures all displays an extended conformation, quite different from the well-folded conformation of Trm5b from Methanocaldococcus jannaschii reported previously, despite their similar overall architectures. To rule out the possibilities of crystallisation artefacts, we conducted the fluorescence resonance energy transfer (FRET) experiments. The FRET data suggested that PaTrm5a adopts a naturally extended conformation in solution, and therefore the open conformation is a genuine state of PaTrm5a.
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Affiliation(s)
- Caiyan Wang
- State Key Laboratory for Biocontrol, School of Life Sciences, The Sun Yat-Sen University, Guangzhou, Guangdong 510275, People’s Republic of China,Center for Cellular & Structural biology, The Sun Yat-Sen University, 132 E. Circle Rd., University City, Guangzhou, Guangdong 510006, People’s Republic of China
| | - Qian Jia
- State Key Laboratory for Biocontrol, School of Life Sciences, The Sun Yat-Sen University, Guangzhou, Guangdong 510275, People’s Republic of China,Center for Cellular & Structural biology, The Sun Yat-Sen University, 132 E. Circle Rd., University City, Guangzhou, Guangdong 510006, People’s Republic of China
| | - Ran Chen
- State Key Laboratory for Biocontrol, School of Life Sciences, The Sun Yat-Sen University, Guangzhou, Guangdong 510275, People’s Republic of China,Center for Cellular & Structural biology, The Sun Yat-Sen University, 132 E. Circle Rd., University City, Guangzhou, Guangdong 510006, People’s Republic of China
| | - Yuming Wei
- State Key Laboratory of Optoelectronic Materials & Technologies, School of Physics, Sun Yat-Sen University, Guangzhou, Guangdong 510006, China
| | - Juntao Li
- State Key Laboratory of Optoelectronic Materials & Technologies, School of Physics, Sun Yat-Sen University, Guangzhou, Guangdong 510006, China
| | - Jie Ma
- State Key Laboratory of Optoelectronic Materials & Technologies, School of Physics, Sun Yat-Sen University, Guangzhou, Guangdong 510006, China
| | - Wei Xie
- State Key Laboratory for Biocontrol, School of Life Sciences, The Sun Yat-Sen University, Guangzhou, Guangdong 510275, People’s Republic of China,Center for Cellular & Structural biology, The Sun Yat-Sen University, 132 E. Circle Rd., University City, Guangzhou, Guangdong 510006, People’s Republic of China,
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12
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Falk MJ, Gai X, Shigematsu M, Vilardo E, Takase R, McCormick E, Christian T, Place E, Pierce EA, Consugar M, Gamper HB, Rossmanith W, Hou YM. A novel HSD17B10 mutation impairing the activities of the mitochondrial RNase P complex causes X-linked intractable epilepsy and neurodevelopmental regression. RNA Biol 2016; 13:477-85. [PMID: 26950678 DOI: 10.1080/15476286.2016.1159381] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
We report a Caucasian boy with intractable epilepsy and global developmental delay. Whole-exome sequencing identified the likely genetic etiology as a novel p.K212E mutation in the X-linked gene HSD17B10 for mitochondrial short-chain dehydrogenase/reductase SDR5C1. Mutations in HSD17B10 cause the HSD10 disease, traditionally classified as a metabolic disorder due to the role of SDR5C1 in fatty and amino acid metabolism. However, SDR5C1 is also an essential subunit of human mitochondrial RNase P, the enzyme responsible for 5'-processing and methylation of purine-9 of mitochondrial tRNAs. Here we show that the p.K212E mutation impairs the SDR5C1-dependent mitochondrial RNase P activities, and suggest that the pathogenicity of p.K212E is due to a general mitochondrial dysfunction caused by reduction in SDR5C1-dependent maturation of mitochondrial tRNAs.
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Affiliation(s)
- Marni J Falk
- a Division of Human Genetics , Department of Pediatrics, The Children's Hospital of Philadelphia , Philadelphia , PA , USA.,b Department of Pediatrics , University of Pennsylvania Perelman School of Medicine , Philadelphia , PA , USA
| | - Xiaowu Gai
- c Center for Personalized Medicine, Children's Hospital Los Angeles , Los Angeles , CA , USA
| | - Megumi Shigematsu
- d Department of Biochemistry and Molecular Biology , Thomas Jefferson University , Philadelphia , PA , USA
| | - Elisa Vilardo
- e Center for Anatomy and Cell Biology, Medical University of Vienna , Vienna , Austria
| | - Ryuichi Takase
- d Department of Biochemistry and Molecular Biology , Thomas Jefferson University , Philadelphia , PA , USA
| | - Elizabeth McCormick
- a Division of Human Genetics , Department of Pediatrics, The Children's Hospital of Philadelphia , Philadelphia , PA , USA
| | - Thomas Christian
- d Department of Biochemistry and Molecular Biology , Thomas Jefferson University , Philadelphia , PA , USA
| | - Emily Place
- a Division of Human Genetics , Department of Pediatrics, The Children's Hospital of Philadelphia , Philadelphia , PA , USA.,f Massachusetts Eye and Ear Infirmary, Harvard Medical School , Boston , MA , USA
| | - Eric A Pierce
- f Massachusetts Eye and Ear Infirmary, Harvard Medical School , Boston , MA , USA
| | - Mark Consugar
- f Massachusetts Eye and Ear Infirmary, Harvard Medical School , Boston , MA , USA
| | - Howard B Gamper
- d Department of Biochemistry and Molecular Biology , Thomas Jefferson University , Philadelphia , PA , USA
| | - Walter Rossmanith
- e Center for Anatomy and Cell Biology, Medical University of Vienna , Vienna , Austria
| | - Ya-Ming Hou
- d Department of Biochemistry and Molecular Biology , Thomas Jefferson University , Philadelphia , PA , USA
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13
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Abstract
Methyl transfer from S-adenosyl methionine (abbreviated as AdoMet) to biologically active molecules such as mRNAs and tRNAs is one of the most fundamental and widespread reactions in nature, occurring in all three domains of life. The measurement of kinetic constants of AdoMet-dependent methyl transfer is therefore important for understanding the reaction mechanism in the context of biology. When kinetic constants of methyl transfer are measured in steady state over multiple rounds of turnover, the meaning of these constants is difficult to define and is often limited by non-chemical steps of the reaction, such as product release after each turnover. Here, the measurement of kinetic constants of methyl transfer by tRNA methyltransferases in rapid equilibrium binding condition for one methyl transfer is described. The advantage of such a measurement is that the meaning of kinetic constants can be directly assigned to the steps associated with the chemistry of methyl transfer, including the substrate binding affinity to the methyltransferase, the pre-chemistry re-arrangement of the active site, and the chemical step of methyl transfer. An additional advantage is that kinetic constants measured for one methyl transfer can be correlated with structural information of the methyltransferase to gain direct insight into its reaction mechanism.
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14
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Structural basis for methyl-donor-dependent and sequence-specific binding to tRNA substrates by knotted methyltransferase TrmD. Proc Natl Acad Sci U S A 2015; 112:E4197-205. [PMID: 26183229 DOI: 10.1073/pnas.1422981112] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The deep trefoil knot architecture is unique to the SpoU and tRNA methyltransferase D (TrmD) (SPOUT) family of methyltransferases (MTases) in all three domains of life. In bacteria, TrmD catalyzes the N(1)-methylguanosine (m(1)G) modification at position 37 in transfer RNAs (tRNAs) with the (36)GG(37) sequence, using S-adenosyl-l-methionine (AdoMet) as the methyl donor. The m(1)G37-modified tRNA functions properly to prevent +1 frameshift errors on the ribosome. Here we report the crystal structure of the TrmD homodimer in complex with a substrate tRNA and an AdoMet analog. Our structural analysis revealed the mechanism by which TrmD binds the substrate tRNA in an AdoMet-dependent manner. The trefoil-knot center, which is structurally conserved among SPOUT MTases, accommodates the adenosine moiety of AdoMet by loosening/retightening of the knot. The TrmD-specific regions surrounding the trefoil knot recognize the methionine moiety of AdoMet, and thereby establish the entire TrmD structure for global interactions with tRNA and sequential and specific accommodations of G37 and G36, resulting in the synthesis of m(1)G37-tRNA.
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15
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Young AP, Bandarian V. Mechanistic Studies of the Radical S-Adenosyl-L-methionine Enzyme 4-Demethylwyosine Synthase Reveal the Site of Hydrogen Atom Abstraction. Biochemistry 2015; 54:3569-72. [PMID: 26052987 DOI: 10.1021/acs.biochem.5b00476] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
TYW1 catalyzes the formation of 4-demethylwyosine via the condensation of N-methylguanosine (m¹G) with carbons 2 and 3 of pyruvate. In this study, labeled transfer ribonucleic acid (tRNA) and pyruvate were utilized to determine the site of hydrogen atom abstraction and regiochemistry of the pyruvate addition. tRNA containing a ²H-labeled m¹G methyl group was used to identify the methyl group of m¹G as the site of hydrogen atom abstraction by 5'-deoxyadenosyl radical. [2-¹³C₁-3,3,3-²H₃]Pyruvate was used to demonstrate retention of all the pyruvate protons, indicating that C2 of pyruvate forms the bridging carbon of the imidazoline ring and C3 the methyl.
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Affiliation(s)
- Anthony P Young
- Department of Chemistry and Biochemistry, University of Arizona, 1041 East Lowell Street, Tucson, Arizona 85721-0088, United States
| | - Vahe Bandarian
- Department of Chemistry and Biochemistry, University of Arizona, 1041 East Lowell Street, Tucson, Arizona 85721-0088, United States
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16
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A divalent metal ion-dependent N(1)-methyl transfer to G37-tRNA. ACTA ACUST UNITED AC 2014; 21:1351-1360. [PMID: 25219964 DOI: 10.1016/j.chembiol.2014.07.023] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 07/20/2014] [Accepted: 07/22/2014] [Indexed: 01/09/2023]
Abstract
The catalytic mechanism of the majority of S-adenosyl methionine (AdoMet)-dependent methyl transferases requires no divalent metal ions. Here we report that methyl transfer from AdoMet to N(1) of G37-tRNA, catalyzed by the bacterial TrmD enzyme, is strongly dependent on divalent metal ions and that Mg(2+) is the most physiologically relevant. Kinetic isotope analysis, metal rescue, and spectroscopic measurements indicate that Mg(2+) is not involved in substrate binding, but in promoting methyl transfer. On the basis of the pH-activity profile indicating one proton transfer during the TrmD reaction, we propose a catalytic mechanism in which the role of Mg(2+) is to help to increase the nucleophilicity of N(1) of G37 and stabilize the negative developing charge on O(6) during attack on the methyl sulfonium of AdoMet. This work demonstrates how Mg(2+) contributes to the catalysis of AdoMet-dependent methyl transfer in one of the most crucial posttranscriptional modifications to tRNA.
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17
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Urbonavičius J, Meškys R, Grosjean H. Biosynthesis of wyosine derivatives in tRNA(Phe) of Archaea: role of a remarkable bifunctional tRNA(Phe):m1G/imG2 methyltransferase. RNA (NEW YORK, N.Y.) 2014; 20:747-753. [PMID: 24837075 PMCID: PMC4024628 DOI: 10.1261/rna.043315.113] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The presence of tricyclic wyosine derivatives 3'-adjacent to anticodon is a hallmark of tRNA(Phe) in eukaryotes and archaea. In yeast, formation of wybutosine (yW) results from five enzymes acting in a strict sequential order. In archaea, the intermediate compound imG-14 (4-demethylwyosine) is a target of three different enzymes, leading to the formation of distinct wyosine derivatives (yW-86, imG, and imG2). We focus here on a peculiar methyltransferase (aTrm5a) that catalyzes two distinct reactions: N(1)-methylation of guanosine and C(7)-methylation of imG-14, whose function is to allow the production of isowyosine (imG2), an intermediate of the 7-methylwyosine (mimG) biosynthetic pathway. Based on the formation of mesomeric forms of imG-14, a rationale for such dual enzymatic activities is proposed. This bifunctional tRNA:m(1)G/imG2 methyltransferase, acting on two chemically distinct guanosine derivatives located at the same position of tRNA(Phe), is unique to certain archaea and has no homologs in eukaryotes. This enzyme here referred to as Taw22, probably played an important role in the emergence of the multistep biosynthetic pathway of wyosine derivatives in archaea and eukaryotes.
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Affiliation(s)
- Jaunius Urbonavičius
- Department of Molecular Microbiology and Biotechnology, Institute of Biochemistry, Vilnius University, LT-08662 Vilnius, Lithuania
- Department of Chemistry and Bioengineering, Vilnius Gediminas Technical University, LT-10223 Vilnius, Lithuania
| | - Rolandas Meškys
- Department of Molecular Microbiology and Biotechnology, Institute of Biochemistry, Vilnius University, LT-08662 Vilnius, Lithuania
| | - Henri Grosjean
- Centre de Génétique Moléculaire, UPR 3404, CNRS, Associée à l'Université Paris-Sud 11, FRC 3115, 91190 Gif-sur-Yvette, France
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18
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Christian T, Gamper H, Hou YM. Conservation of structure and mechanism by Trm5 enzymes. RNA (NEW YORK, N.Y.) 2013; 19:1192-1199. [PMID: 23887145 PMCID: PMC3753926 DOI: 10.1261/rna.039503.113] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 06/06/2013] [Indexed: 06/02/2023]
Abstract
Enzymes of the Trm5 family catalyze methyl transfer from S-adenosyl methionine (AdoMet) to the N¹ of G37 to synthesize m¹ G37-tRNA as a critical determinant to prevent ribosome frameshift errors. Trm5 is specific to eukaryotes and archaea, and it is unrelated in evolution from the bacterial counterpart TrmD, which is a leading anti-bacterial target. The successful targeting of TrmD requires detailed information on Trm5 to avoid cross-species inhibition. However, most information on Trm5 is derived from studies of the archaeal enzyme Methanococcus jannaschii (MjTrm5), whereas little information is available for eukaryotic enzymes. Here we use human Trm5 (Homo sapiens; HsTrm5) as an example of eukaryotic enzymes and demonstrate that it has retained key features of catalytic properties of the archaeal MjTrm5, including the involvement of a general base to mediate one proton transfer. We also address the protease sensitivity of the human enzyme upon expression in bacteria. Using the tRNA-bound crystal structure of the archaeal enzyme as a model, we have identified a single substitution in the human enzyme that improves resistance to proteolysis. These results establish conservation in both the catalytic mechanism and overall structure of Trm5 between evolutionarily distant eukaryotic and archaeal species and validate the crystal structure of the archaeal enzyme as a useful model for studies of the human enzyme.
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19
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Lee KY, Kim JH, Lee KY, Lee J, Lee I, Bae YJ, Lee BJ. Structural characterization of HP1264 reveals a novel fold for the flavin mononucleotide binding protein. Biochemistry 2013; 52:1583-93. [PMID: 23406339 DOI: 10.1021/bi301714a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Complex I (NADH-quinone oxidoreductase) is an enzyme that catalyzes the initial electron transfer from nicotinamide adenine dinucleotide (NADH) to flavin mononucleotide (FMN) bound at the tip of the hydrophilic domain of complex I. The electron flow into complex I is coupled to the generation of a proton gradient across the membrane that is essential for the synthesis of ATP. However, Helicobacter pylori has an unusual complex I that lacks typical NQO1 and NQO2 subunits, both of which are generally included in the NADH dehydrogenase domain of complex I. Here, we determined the solution structure of HP1264, one of the unusual subunits of complex I from H. pylori, which is located in place of NQO2, by three-dimensional nuclear magnetic resonance (NMR) spectroscopy and revealed that HP1264 can bind to FMN through UV-visible, fluorescence, and NMR titration experiments. This result suggests that FMN-bound HP1264 could be involved in the initial electron transfer step of complex I. In addition, HP1264 is structurally most similar to Escherichia coli TusA, which belongs to the SirA-like superfamily having an IF3-like fold in the SCOP database, implying that HP1264 adopts a novel fold for FMN binding. On the basis of the NMR titration data, we propose the candidate residues Ile32, Met34, Leu58, Trp68, and Val71 of HP1264 for the interaction with FMN. Notably, these residues are not conserved in the FMN binding site of any other flavoproteins with known structure. This study of the relationship between the structure and FMN binding property of HP1264 will contribute to improving our understanding of flavoprotein structure and the electron transfer mechanism of complex I.
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Affiliation(s)
- Ki-Young Lee
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Korea
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20
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Sakaguchi R, Giessing A, Dai Q, Lahoud G, Liutkeviciute Z, Klimasauskas S, Piccirilli J, Kirpekar F, Hou YM. Recognition of guanosine by dissimilar tRNA methyltransferases. RNA (NEW YORK, N.Y.) 2012; 18:1687-1701. [PMID: 22847817 PMCID: PMC3425783 DOI: 10.1261/rna.032029.111] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 06/16/2012] [Indexed: 06/01/2023]
Abstract
Guanosines are important for biological activities through their specific functional groups that are recognized for RNA or protein interactions. One example is recognition of N(1) of G37 in tRNA by S-adenosyl-methionine (AdoMet)-dependent tRNA methyltransferases to synthesize m(1)G37-tRNA, which is essential for translational fidelity in all biological domains. Synthesis of m(1)G37-tRNA is catalyzed by TrmD in bacteria and by Trm5 in eukarya and archaea, using unrelated and dissimilar structural folds. This raises the question of how dissimilar proteins recognize the same guanosine. Here we probe the mechanism of discrimination among functional groups of guanosine by TrmD and Trm5. Guanosine analogs were systematically introduced into tRNA through a combination of chemical and enzymatic synthesis. Single turnover kinetic assays and thermodynamic analysis of the effect of each analog on m(1)G37-tRNA synthesis reveal that TrmD and Trm5 discriminate functional groups differently. While both recognize N(1) and O(6) of G37, TrmD places a much stronger emphasis on these functional groups than Trm5. While the exocyclic 2-amino group of G37 is important for TrmD, it is dispensable for Trm5. In addition, while an adjacent G36 is obligatory for TrmD, it is nonessential for Trm5. These results depict a more rigid requirement of guanosine functional groups for TrmD than for Trm5. However, the sensitivity of both enzymes to analog substitutions, together with an experimental revelation of their low cellular concentrations relative to tRNA substrates, suggests a model in which these enzymes rapidly screen tRNA by direct recognition of G37 in order to monitor the global state of m(1)G37-tRNA.
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Affiliation(s)
- Reiko Sakaguchi
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
| | - Anders Giessing
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Qing Dai
- Departments of Biochemistry & Molecular Biology, and Chemistry, Gordon Center for Integrative Science, University of Chicago, Chicago, Illinois 60637, USA
| | - Georges Lahoud
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
| | - Zita Liutkeviciute
- Department of Biological DNA Modification, Institute of Biotechnology, Vilnius University, LT-02241 Vilnius, Lithuania
| | - Saulius Klimasauskas
- Department of Biological DNA Modification, Institute of Biotechnology, Vilnius University, LT-02241 Vilnius, Lithuania
| | - Joseph Piccirilli
- Departments of Biochemistry & Molecular Biology, and Chemistry, Gordon Center for Integrative Science, University of Chicago, Chicago, Illinois 60637, USA
| | - Finn Kirpekar
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Ya-Ming Hou
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
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21
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Lahoud G, Goto-Ito S, Yoshida KI, Ito T, Yokoyama S, Hou YM. Differentiating analogous tRNA methyltransferases by fragments of the methyl donor. RNA (NEW YORK, N.Y.) 2011; 17:1236-1246. [PMID: 21602303 PMCID: PMC3138561 DOI: 10.1261/rna.2706011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2011] [Accepted: 04/15/2011] [Indexed: 05/30/2023]
Abstract
Bacterial TrmD and eukaryotic-archaeal Trm5 form a pair of analogous tRNA methyltransferase that catalyze methyl transfer from S-adenosyl methionine (AdoMet) to N(1) of G37, using catalytic motifs that share no sequence or structural homology. Here we show that natural and synthetic analogs of AdoMet are unable to distinguish TrmD from Trm5. Instead, fragments of AdoMet, adenosine and methionine, are selectively inhibitory of TrmD rather than Trm5. Detailed structural information of the two enzymes in complex with adenosine reveals how Trm5 escapes targeting by adopting an altered structure, whereas TrmD is trapped by targeting due to its rigid structure that stably accommodates the fragment. Free energy analysis exposes energetic disparities between the two enzymes in how they approach the binding of AdoMet versus fragments and provides insights into the design of inhibitors selective for TrmD.
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Affiliation(s)
- Georges Lahoud
- Thomas Jefferson University, Department of Biochemistry and Molecular Biology, Philadelphia, Pennsylvania 19107, USA
| | - Sakurako Goto-Ito
- RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro, Tsurumi, Yokohama, Kanagawa 230-0045, Japan
- Department of Biophysics and Biochemistry, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ken-ichi Yoshida
- RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro, Tsurumi, Yokohama, Kanagawa 230-0045, Japan
- Department of Biophysics and Biochemistry, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takuhiro Ito
- RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro, Tsurumi, Yokohama, Kanagawa 230-0045, Japan
| | - Shigeyuki Yokoyama
- RIKEN Systems and Structural Biology Center, 1-7-22 Suehiro, Tsurumi, Yokohama, Kanagawa 230-0045, Japan
- Department of Biophysics and Biochemistry, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ya-Ming Hou
- Thomas Jefferson University, Department of Biochemistry and Molecular Biology, Philadelphia, Pennsylvania 19107, USA
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22
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Christian T, Lahoud G, Liu C, Hoffmann K, Perona JJ, Hou YM. Mechanism of N-methylation by the tRNA m1G37 methyltransferase Trm5. RNA (NEW YORK, N.Y.) 2010; 16:2484-2492. [PMID: 20980671 PMCID: PMC2995409 DOI: 10.1261/rna.2376210] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Accepted: 09/22/2010] [Indexed: 05/30/2023]
Abstract
Trm5 is a eukaryal and archaeal tRNA methyltransferase that catalyzes methyl transfer from S-adenosylmethionine (AdoMet) to the N(1) position of G37 directly 3' to the anticodon. While the biological role of m(1)G37 in enhancing translational fidelity is well established, the catalytic mechanism of Trm5 has remained obscure. To address the mechanism of Trm5 and more broadly the mechanism of N-methylation to nucleobases, we examined the pH-activity profile of an archaeal Trm5 enzyme, and performed structure-guided mutational analysis. The data reveal a marked dependence of enzyme-catalyzed methyl transfer on hydrogen ion equilibria: the single-turnover rate constant for methylation increases by one order of magnitude from pH 6.0 to reach a plateau at pH 7.0. This suggests a mechanism involving proton transfer from G37 as the key element in catalysis. Consideration of the kinetic data in light of the Trm5-tRNA-AdoMet ternary cocrystal structure, determined in a precatalytic conformation, suggests that proton transfer is associated with an induced fit rearrangement of the complex that precedes formation of the reactive configuration in the active site. Key roles for the conserved R145 side chain in stabilizing a proposed oxyanion at G37-O(6), and for E185 as a general base to accept the proton from G37-N(1), are suggested based on the mutational analysis.
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Affiliation(s)
- Thomas Christian
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
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23
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Christian T, Lahoud G, Liu C, Hou YM. Control of catalytic cycle by a pair of analogous tRNA modification enzymes. J Mol Biol 2010; 400:204-17. [PMID: 20452364 DOI: 10.1016/j.jmb.2010.05.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2009] [Revised: 04/13/2010] [Accepted: 05/03/2010] [Indexed: 10/19/2022]
Abstract
Enzymes that use distinct active site structures to perform identical reactions are known as analogous enzymes. The isolation of analogous enzymes suggests the existence of multiple enzyme structural pathways that can catalyze the same chemical reaction. A fundamental question concerning analogous enzymes is whether their distinct active-site structures would confer the same or different kinetic constraints to the chemical reaction, particularly with respect to the control of enzyme turnover. Here, we address this question with the analogous enzymes of bacterial TrmD and its eukaryotic and archaeal counterpart Trm5. TrmD and Trm5 catalyze methyl transfer to synthesize the m1G37 base at the 3' position adjacent to the tRNA anticodon, using S-adenosyl methionine (AdoMet) as the methyl donor. TrmD features a trefoil-knot active-site structure whereas Trm5 features the Rossmann fold. Pre-steady-state analysis revealed that product synthesis by TrmD proceeds linearly with time, whereas that by Trm5 exhibits a rapid burst followed by a slower and linear increase with time. The burst kinetics of Trm5 suggests that product release is the rate-limiting step of the catalytic cycle, consistent with the observation of higher enzyme affinity to the products of tRNA and AdoMet. In contrast, the lack of burst kinetics of TrmD suggests that its turnover is controlled by a step required for product synthesis. Although TrmD exists as a homodimer, it showed half-of-the-sites reactivity for tRNA binding and product synthesis. The kinetic differences between TrmD and Trm5 are parallel with those between the two classes of aminoacyl-tRNA synthetases, which use distinct active site structures to catalyze tRNA aminoacylation. This parallel suggests that the findings have a fundamental importance for enzymes that catalyze both methyl and aminoacyl transfer to tRNA in the decoding process.
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Affiliation(s)
- Thomas Christian
- Thomas Jefferson University, Department of Biochemistry and Molecular Biology, 233 South 10th Street, BLSB 220, Philadelphia, PA 19107, USA
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24
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Hou YM, Perona JJ. Stereochemical mechanisms of tRNA methyltransferases. FEBS Lett 2009; 584:278-86. [PMID: 19944101 DOI: 10.1016/j.febslet.2009.11.075] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Revised: 11/18/2009] [Accepted: 11/19/2009] [Indexed: 12/31/2022]
Abstract
Methylation of tRNA on the four canonical bases adds structural complexity to the molecule, and improves decoding specificity and efficiency. While many tRNA methylases are known, detailed insight into the catalytic mechanism is only available in a few cases. Of interest among all tRNA methylases is the structural basis for nucleotide selection, by which the specificity is limited to a single site, or broadened to multiple sites. General themes in catalysis include the basis for rate acceleration at highly diverse nucleophilic centers for methyl transfer, using S-adenosylmethionine as a cofactor. Studies of tRNA methylases have also yielded insights into molecular evolution, particularly in the case of enzymes that recognize distinct structures to perform identical reactions at the same target nucleotide.
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Affiliation(s)
- Ya-Ming Hou
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 233 South 10th St., Philadelphia, PA 19107, USA.
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25
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Tertiary structure checkpoint at anticodon loop modification in tRNA functional maturation. Nat Struct Mol Biol 2009; 16:1109-15. [PMID: 19749755 DOI: 10.1038/nsmb.1653] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Accepted: 06/29/2009] [Indexed: 11/08/2022]
Abstract
tRNA precursors undergo a maturation process, involving nucleotide modifications and folding into the L-shaped tertiary structure. The N1-methylguanosine at position 37 (m1G37), 3' adjacent to the anticodon, is essential for translational fidelity and efficiency. In archaea and eukaryotes, Trm5 introduces the m1G37 modification into all tRNAs bearing G37. Here we report the crystal structures of archaeal Trm5 (aTrm5) in complex with tRNA(Leu) or tRNA(Cys). The D2-D3 domains of aTrm5 discover and modify G37, independently of the tRNA sequences. D1 is connected to D2-D3 through a flexible linker and is designed to recognize the shape of the tRNA outer corner, as a hallmark of the completed L shape formation. This interaction by D1 lowers the K(m) value for tRNA, enabling the D2-D3 catalysis. Thus, we propose that aTrm5 provides the tertiary structure checkpoint in tRNA maturation.
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26
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Goto-Ito S, Ito T, Ishii R, Muto Y, Bessho Y, Yokoyama S. Crystal structure of archaeal tRNA(m(1)G37)methyltransferase aTrm5. Proteins 2009; 72:1274-89. [PMID: 18384044 DOI: 10.1002/prot.22019] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Methylation of the N1 atom of guanosine at position 37 in tRNA, the position 3'-adjacent to the anticodon, generates the modified nucleoside m(1)G37. In archaea and eukaryotes, m(1)G37 synthesis is catalyzed by tRNA(m(1)G37)methyltransferase (archaeal or eukaryotic Trm5, a/eTrm5). Here we report the crystal structure of archaeal Trm5 (aTrm5) from Methanocaldococcus jannaschii (formerly known as Methanococcus jannaschii) in complex with the methyl donor analogue at 2.2 A resolution. The crystal structure revealed that the entire protein is composed of three structural domains, D1, D2, and D3. In the a/eTrm5 primary structures, D2 and D3 are highly conserved, while D1 is not conserved. The D3 structure is the Rossmann fold, which is the hallmark of the canonical class-I methyltransferases. The a/eTrm5-defining domain, D2, exhibits structural similarity to some class-I methyltransferases. In contrast, a DALI search with the D1 structure yielded no structural homologues. In the crystal structure, D3 contacts both D1 and D2. The residues involved in the D1:D3 interactions are not conserved, while those participating in the D2:D3 interactions are well conserved. D1 and D2 do not contact each other, and the linker between them is disordered. aTrm5 fragments corresponding to the D1 and D2-D3 regions were prepared in a soluble form. The NMR analysis of the D1 fragment revealed that D1 is well folded by itself, and it did not interact with either the D2-D3 fragment or the tRNA. The NMR analysis of the D2-D3 fragment revealed that it is well folded, independently of D1, and that it interacts with tRNA. Furthermore, the D2-D3 fragment was as active as the full-length enzyme for tRNA methylation. The positive charges on the surface of D2-D3 may be involved in tRNA binding. Therefore, these findings suggest that the interaction between D1 and D3 is not persistent, and that the D2-D3 region plays the major role in tRNA methylation.
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Affiliation(s)
- Sakurako Goto-Ito
- Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
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Christian T, Hou YM. Distinct determinants of tRNA recognition by the TrmD and Trm5 methyl transferases. J Mol Biol 2007; 373:623-32. [PMID: 17868690 PMCID: PMC2064070 DOI: 10.1016/j.jmb.2007.08.010] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2007] [Accepted: 08/03/2007] [Indexed: 11/24/2022]
Abstract
TrmD and Trm5 are, respectively, the bacterial and eukarya/archaea methyl transferases that catalyze transfer of the methyl group from S-adenosyl methionine (AdoMet) to the N1 position of G37 in tRNA to synthesize m1G37-tRNA. The m1G37 modification prevents tRNA frameshifts on the ribosome by assuring correct codon-anticodon pairings, and thus is essential for the fidelity of protein synthesis. Although TrmD and Trm5 are derived from unrelated AdoMet families and recognize the cofactor using distinct motifs, the question of whether they select G37 on tRNA by the same, or different, mechanism has not been answered. Here we address this question by kinetic analysis of tRNA truncation mutants that lack domains typically present in the canonical L shaped structure, and by evaluation of the site of modification on tRNA variants with an expanded or contracted anticodon loop. With both experimental approaches, we show that TrmD and Trm5 exhibit separate and distinct mode of tRNA recognition, suggesting that they evolved by independent and non-overlapping pathways from their unrelated AdoMet families. Our results also shed new light onto the significance of the m1G37 modification in the controversial quadruplet-pairing model of tRNA frameshift suppressors.
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Affiliation(s)
| | - Ya-Ming Hou
- *Corresponding author. Telephone: 215-503-4480; Fax: 215-503-4954;
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