1
|
Peng GX, Zhang Y, Wang QQ, Li QR, Xu H, Wang ED, Zhou XL. The human tRNA taurine modification enzyme GTPBP3 is an active GTPase linked to mitochondrial diseases. Nucleic Acids Res 2021; 49:2816-2834. [PMID: 33619562 PMCID: PMC7969015 DOI: 10.1093/nar/gkab104] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 02/03/2021] [Accepted: 02/09/2021] [Indexed: 01/03/2023] Open
Abstract
GTPBP3 and MTO1 cooperatively catalyze 5-taurinomethyluridine (τm5U) biosynthesis at the 34th wobble position of mitochondrial tRNAs. Mutations in tRNAs, GTPBP3 or MTO1, causing τm5U hypomodification, lead to various diseases. However, efficient in vitro reconstitution and mechanistic study of τm5U modification have been challenging, in part due to the lack of pure and active enzymes. A previous study reported that purified human GTPBP3 (hGTPBP3) is inactive in GTP hydrolysis. Here, we identified the mature form of hGTPBP3 and showed that hGTPBP3 is an active GTPase in vitro that is critical for tRNA modification in vivo. Unexpectedly, the isolated G domain and a mutant with the N-terminal domain truncated catalyzed GTP hydrolysis to only a limited extent, exhibiting high Km values compared with that of the mature enzyme. We further described several important pathogenic mutations of hGTPBP3, associated with alterations in hGTPBP3 localization, structure and/or function in vitro and in vivo. Moreover, we discovered a novel cytoplasm-localized isoform of hGTPBP3, indicating an unknown potential noncanonical function of hGTPBP3. Together, our findings established, for the first time, the GTP hydrolysis mechanism of hGTPBP3 and laid a solid foundation for clarifying the τm5U modification mechanism and etiology of τm5U deficiency-related diseases.
Collapse
Affiliation(s)
- Gui-Xin Peng
- 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, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China.,School of Life Science and Technology, ShanghaiTech University, 393 Middle Hua Xia Road, Shanghai 201210, China
| | - Yong Zhang
- 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, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Qin-Qin Wang
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Hua Xia Road, Shanghai 201210, China
| | - Qing-Run Li
- CAS Key Laboratory of Systems Biology, CAS Center for Excellence in Molecular Cell Sciences, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Hong Xu
- Shanghai Key Laboratory of Embryo Original Diseases, Shanghai Municipal Key Clinical Specialty, the International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, 910 Heng Shan Road, Shanghai 200030, China
| | - En-Duo Wang
- 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, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China.,School of Life Science and Technology, ShanghaiTech University, 393 Middle Hua Xia Road, Shanghai 201210, China
| | - Xiao-Long Zhou
- 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, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| |
Collapse
|
2
|
Laporte D, Huot JL, Bader G, Enkler L, Senger B, Becker HD. Exploring the evolutionary diversity and assembly modes of multi-aminoacyl-tRNA synthetase complexes: lessons from unicellular organisms. FEBS Lett 2014; 588:4268-78. [PMID: 25315413 DOI: 10.1016/j.febslet.2014.10.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 10/03/2014] [Accepted: 10/06/2014] [Indexed: 10/24/2022]
Abstract
Aminoacyl-tRNA synthetases (aaRSs) are ubiquitous and ancient enzymes, mostly known for their essential role in generating aminoacylated tRNAs. During the last two decades, many aaRSs have been found to perform additional and equally crucial tasks outside translation. In metazoans, aaRSs have been shown to assemble, together with non-enzymatic assembly proteins called aaRSs-interacting multifunctional proteins (AIMPs), into so-called multi-synthetase complexes (MSCs). Metazoan MSCs are dynamic particles able to specifically release some of their constituents in response to a given stimulus. Upon their release from MSCs, aaRSs can reach other subcellular compartments, where they often participate to cellular processes that do not exploit their primary function of synthesizing aminoacyl-tRNAs. The dynamics of MSCs and the expansion of the aaRSs functional repertoire are features that are so far thought to be restricted to higher and multicellular eukaryotes. However, much can be learnt about how MSCs are assembled and function from apparently 'simple' organisms. Here we provide an overview on the diversity of these MSCs, their composition, mode of assembly and the functions that their constituents, namely aaRSs and AIMPs, exert in unicellular organisms.
Collapse
Affiliation(s)
- Daphné Laporte
- UMR 'Génétique Moléculaire, Génomique, Microbiologie', CNRS, Université de Strasbourg, 21 rue René Descartes, 67084 Strasbourg Cedex, France
| | - Jonathan L Huot
- UMR 'Génétique Moléculaire, Génomique, Microbiologie', CNRS, Université de Strasbourg, 21 rue René Descartes, 67084 Strasbourg Cedex, France
| | - Gaétan Bader
- UMR 'Génétique Moléculaire, Génomique, Microbiologie', CNRS, Université de Strasbourg, 21 rue René Descartes, 67084 Strasbourg Cedex, France
| | - Ludovic Enkler
- UMR 'Génétique Moléculaire, Génomique, Microbiologie', CNRS, Université de Strasbourg, 21 rue René Descartes, 67084 Strasbourg Cedex, France
| | - Bruno Senger
- UMR 'Génétique Moléculaire, Génomique, Microbiologie', CNRS, Université de Strasbourg, 21 rue René Descartes, 67084 Strasbourg Cedex, France
| | - Hubert Dominique Becker
- UMR 'Génétique Moléculaire, Génomique, Microbiologie', CNRS, Université de Strasbourg, 21 rue René Descartes, 67084 Strasbourg Cedex, France.
| |
Collapse
|
3
|
Zhou XL, Du DH, Tan M, Lei HY, Ruan LL, Eriani G, Wang ED. Role of tRNA amino acid-accepting end in aminoacylation and its quality control. Nucleic Acids Res 2011; 39:8857-68. [PMID: 21775341 PMCID: PMC3203616 DOI: 10.1093/nar/gkr595] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Aminoacyl–tRNA synthetases (aaRSs) are remarkable enzymes that are in charge of the accurate recognition and ligation of amino acids and tRNA molecules. The greatest difficulty in accurate aminoacylation appears to be in discriminating between highly similar amino acids. To reduce mischarging of tRNAs by non-cognate amino acids, aaRSs have evolved an editing activity in a second active site to cleave the incorrect aminoacyl–tRNAs. Editing occurs after translocation of the aminoacyl–CCA76 end to the editing site, switching between a hairpin and a helical conformation for aminoacylation and editing. Here, we studied the consequence of nucleotide changes in the CCA76 accepting end of tRNALeu during the aminoacylation and editing reactions. The analysis showed that the terminal A76 is essential for both reactions, suggesting that critical interactions occur in the two catalytic sites. Substitutions of C74 and C75 selectively decreased aminoacylation keeping nearly unaffected editing. These mutations might favor the regular helical conformation required to reach the editing site. Mutating the editing domain residues that contribute to CCA76 binding reduced the aminoacylation fidelity leading to cell-toxicity in the presence of non-cognate amino acids. Collectively, the data show how protein synthesis quality is controlled by the CCA76 homogeneity of tRNAs.
Collapse
Affiliation(s)
- Xiao-Long Zhou
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, The Chinese Academy of Sciences, Shanghai 200031, China
| | | | | | | | | | | | | |
Collapse
|
4
|
Hao R, Zhao MW, Hao ZX, Yao YN, Wang ED. A T-stem slip in human mitochondrial tRNALeu(CUN) governs its charging capacity. Nucleic Acids Res 2005; 33:3606-13. [PMID: 15972857 PMCID: PMC1157101 DOI: 10.1093/nar/gki677] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The human mitochondrial tRNALeu(CUN) [hmtRNALeu(CUN)] corresponds to the most abundant codon for leucine in human mitochondrial protein genes. Here, in vitro studies reveal that the U48C substitution in hmtRNALeu(CUN), which corresponds to the pathological T12311C gene mutation, improved the aminoacylation efficiency of hmtRNALeu(CUN). Enzymatic probing suggested a more flexible secondary structure in the wild-type hmtRNALeu(CUN) transcript compared with the U48C mutant. Structural analysis revealed that the flexibility of hmtRNALeu(CUN) facilitates a T-stem slip resulting in two potential tertiary structures. Several rationally designed tRNALeu(CUN) mutants were generated to examine the structural and functional consequences of the T-stem slip. Examination of these hmtRNALeu(CUN) mutants indicated that the T-stem slip governs tRNA accepting activity. These results suggest a novel, self-regulation mechanism of tRNA structure and function.
Collapse
Affiliation(s)
- Rui Hao
- Graduate School of the Chinese Academy of Sciences, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, The Chinese Academy of Sciences320 Yue Yang Road, Shanghai 200031, People's Republic of China
| | - Ming-Wei Zhao
- Graduate School of the Chinese Academy of Sciences, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, The Chinese Academy of Sciences320 Yue Yang Road, Shanghai 200031, People's Republic of China
| | - Zhan-Xi Hao
- Graduate School of the Chinese Academy of Sciences, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, The Chinese Academy of Sciences320 Yue Yang Road, Shanghai 200031, People's Republic of China
| | | | - En-Duo Wang
- Graduate School of the Chinese Academy of Sciences, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, The Chinese Academy of Sciences320 Yue Yang Road, Shanghai 200031, People's Republic of China
- To whom correspondence should be addressed. Tel: +86 21 54921241; Fax: +86 21 54921011;
| |
Collapse
|
5
|
Xu MG, Li J, Du X, Wang ED. Groups on the side chain of T252 in Escherichia coli leucyl-tRNA synthetase are important for discrimination of amino acids and cell viability. Biochem Biophys Res Commun 2004; 318:11-6. [PMID: 15110746 DOI: 10.1016/j.bbrc.2004.03.180] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2004] [Indexed: 11/16/2022]
Abstract
Leucyl-tRNA synthetase (LeuRS) catalyzes the leucylation of tRNA(Leu). To maintain the fidelity of protein biosynthesis, LeuRS also catalyzes the editing reaction. In the present work, highly conserved T252 in the T-rich region within CP1 domain of Escherichia coli LeuRS was mutated to G, D, or E. Steady-state kinetic of aminoacylation, and combined editing assays indicated that not only the size of the amino acid but also the absence of hydrogen bonds between T252 and adjacent molecules may affect the editing. It is further confirmed by in vivo experiments using the temperature-sensitive strain KL231 (DeltaleuS), which revealed the arrested growth of bacterial cells bearing mutants with highly impaired editing activity in the presence of leucine analog.
Collapse
Affiliation(s)
- Min-Gang Xu
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, The Chinese Academy of Sciences, Shanghai 200031, China
| | | | | | | |
Collapse
|
6
|
Du X, Wang ED. E292 is important for the aminoacylation activity of Escherichia coli leucyl-tRNA synthetase. JOURNAL OF PROTEIN CHEMISTRY 2003; 22:71-6. [PMID: 12739900 DOI: 10.1023/a:1023071928587] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Escherichia coli leucyl-tRNA synthetase (LeuRS) has a large connecting polypeptide (CP1) inserted into its active site. It was demonstrated that the peptide bond between E292-A293 was crucial for the aminoacylation activity of E. coli LeuRS. To investigate the effect of E292 on the function of Escherichia coli LeuRS, E292 was mutated to K, F, S, D, Q and A. These mutations at 292 did not change the specific activity of the amino acid activation reaction. Though the conformational change of these mutants was not detected in CD, their aminoacylation activities were impaired to varying extents. The mutation of E to K decreased the aminoacylation activity to the largest extent. Analysis of the Km values of these mutants for the three substrates showed that the E292 was not involved in the binding of leucine and that all mutants had stronger binding with ATP.
Collapse
Affiliation(s)
- Xing Du
- State Key Laboratory of Molecular Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | | |
Collapse
|
7
|
Xu MG, Chen JF, Martin F, Zhao MW, Eriani G, Wang ED. Leucyl-tRNA synthetase consisting of two subunits from hyperthermophilic bacteria Aquifex aeolicus. J Biol Chem 2002; 277:41590-6. [PMID: 12196521 DOI: 10.1074/jbc.m205126200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In a hyperthermophilic bacterium, Aquifex aeolicus, leucyl-tRNA synthetase (LeuRS) consists of two non-identical polypeptide subunits (alpha and beta), different from the canonical LeuRS, which has a single polypeptide chain. By PCR, using genome DNA of A. aeolicus as a template, genes encoding the alpha and beta subunits were amplified and cloned in Escherichia coli. The alpha subunit could not be expressed stably in vivo, whereas the beta subunit was overproduced and purified by a simple procedure. The beta subunit was inactive in catalysis but was able to bind tRNA(Leu). Interestingly, the heterodimer alphabeta-LeuRS could be overproduced in E. coli cells containing both genes and was purified to 95% homogeneity as a hybrid dimer. The kinetics of A. aeolicus LeuRS in pre-steady and steady states and cross-recognition of LeuRS and tRNA(Leu) from A. aeolicus and E. coli were studied. Magnesium concentration, pH value, and temperature aminoacylation optima were determined to be 12 mm, 7.8, and 70 degrees C, respectively. Under optimal conditions, A. aeolicus alphabeta-LeuRS is stable up to 65 degrees C.
Collapse
Affiliation(s)
- Min-Gang Xu
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, China
| | | | | | | | | | | |
Collapse
|
8
|
Abstract
Aminoacyl-tRNAs are substrates for translation and are pivotal in determining how the genetic code is interpreted as amino acids. The function of aminoacyl-tRNA synthesis is to precisely match amino acids with tRNAs containing the corresponding anticodon. This is primarily achieved by the direct attachment of an amino acid to the corresponding tRNA by an aminoacyl-tRNA synthetase, although intrinsic proofreading and extrinsic editing are also essential in several cases. Recent studies of aminoacyl-tRNA synthesis, mainly prompted by the advent of whole genome sequencing and the availability of a vast body of structural data, have led to an expanded and more detailed picture of how aminoacyl-tRNAs are synthesized. This article reviews current knowledge of the biochemical, structural, and evolutionary facets of aminoacyl-tRNA synthesis.
Collapse
Affiliation(s)
- M Ibba
- Center for Biomolecular Recognition, IMBG Laboratory B, The Panum Institute, DK-2200, Copenhagen N, Denmark.
| | | |
Collapse
|
9
|
Affiliation(s)
- R D Knight
- Department of Ecology and Evolutionary Biology, Princeton University, New Jersey 08544, USA.
| | | |
Collapse
|