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Błaszczyk E, Płociński P, Lechowicz E, Brzostek A, Dziadek B, Korycka-Machała M, Słomka M, Dziadek J. Depletion of tRNA CCA-adding enzyme in Mycobacterium tuberculosis leads to polyadenylation of transcripts and precursor tRNAs. Sci Rep 2023; 13:20717. [PMID: 38001315 PMCID: PMC10673834 DOI: 10.1038/s41598-023-47944-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 11/20/2023] [Indexed: 11/26/2023] Open
Abstract
In reference to gene annotation, more than half of the tRNA species synthesized by Mycobacterium tuberculosis require the enzymatic addition of the cytosine-cytosine-adenine (CCA) tail, which is indispensable for amino acid charging and tRNA functionality. It makes the mycobacterial CCA-adding enzyme essential for survival of the bacterium and a potential target for novel pipelines in drug discovery avenues. Here, we described the rv3907c gene product, originally annotated as poly(A)polymerase (rv3907c, PcnA) as a functional CCA-adding enzyme (CCAMtb) essential for viability of M. tuberculosis. The depletion of the enzyme affected tRNAs maturation, inhibited bacilli growth, and resulted in abundant accumulation of polyadenylated RNAs. We determined the enzymatic activities displayed by the mycobacterial CCAMtb in vitro and studied the effects of inhibiting of its transcription in bacterial cells. We are the first to properly confirm the existence of RNA polyadenylation in mycobacteria, a previously controversial phenomenon, which we found promoted upon CCA-adding enzyme downexpression.
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Affiliation(s)
- Ewelina Błaszczyk
- Institute of Medical Biology, Polish Academy of Sciences, Lodowa 106, 93-232, Łódź, Poland
| | - Przemysław Płociński
- Institute of Medical Biology, Polish Academy of Sciences, Lodowa 106, 93-232, Łódź, Poland
- Department of Immunology and Infectious Biology, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 12/16, 90-237, Łódź, Poland
| | - Ewelina Lechowicz
- Institute of Medical Biology, Polish Academy of Sciences, Lodowa 106, 93-232, Łódź, Poland
| | - Anna Brzostek
- Institute of Medical Biology, Polish Academy of Sciences, Lodowa 106, 93-232, Łódź, Poland
| | - Bożena Dziadek
- Department of Molecular Microbiology, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 12/16, 90-237, Łódź, Poland
| | | | - Marcin Słomka
- Biobank Lab, Department of Oncobiology and Epigenetics, Faculty of Biology and Environmental Protection, University of Łódź, Pomorska 139, 90-235, Łódź, Poland
| | - Jarosław Dziadek
- Institute of Medical Biology, Polish Academy of Sciences, Lodowa 106, 93-232, Łódź, Poland.
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2
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Hager M, Pöhler MT, Reinhardt F, Wellner K, Hübner J, Betat H, Prohaska S, Mörl M. Substrate Affinity Versus Catalytic Efficiency: Ancestral Sequence Reconstruction of tRNA Nucleotidyltransferases Solves an Enzyme Puzzle. Mol Biol Evol 2022; 39:6835633. [PMID: 36409584 PMCID: PMC9728577 DOI: 10.1093/molbev/msac250] [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] [Indexed: 11/22/2022] Open
Abstract
In tRNA maturation, CCA-addition by tRNA nucleotidyltransferase is a unique and highly accurate reaction. While the mechanism of nucleotide selection and polymerization is well understood, it remains a mystery why bacterial and eukaryotic enzymes exhibit an unexpected and surprisingly low tRNA substrate affinity while they efficiently catalyze the CCA-addition. To get insights into the evolution of this high-fidelity RNA synthesis, the reconstruction and characterization of ancestral enzymes is a versatile tool. Here, we investigate a reconstructed candidate of a 2 billion years old CCA-adding enzyme from Gammaproteobacteria and compare it to the corresponding modern enzyme of Escherichia coli. We show that the ancestral candidate catalyzes an error-free CCA-addition, but has a much higher tRNA affinity compared with the extant enzyme. The consequence of this increased substrate binding is an enhanced reverse reaction, where the enzyme removes the CCA end from the mature tRNA. As a result, the ancestral candidate exhibits a lower catalytic efficiency in vitro as well as in vivo. Furthermore, the efficient tRNA interaction leads to a processive polymerization, while the extant enzyme catalyzes nucleotide addition in a distributive way. Thus, the modern enzymes increased their polymerization efficiency by lowering the binding affinity to tRNA, so that CCA synthesis is efficiently promoted due to a reduced reverse reaction. Hence, the puzzling and at a first glance contradicting and detrimental weak substrate interaction represents a distinct activity enhancement in the evolution of CCA-adding enzymes.
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Affiliation(s)
| | | | - Franziska Reinhardt
- Computational EvoDevo Group, Institute for Computer Science, Leipzig University, Härtelstr. 16-18, 04109 Leipzig, Germany,Interdisciplinary Centre for Bioinformatics, Leipzig University, Härtelstr. 16-18, 04109 Leipzig, Germany
| | - Karolin Wellner
- Institute for Biochemistry, Leipzig University, Brüderstraße 34, D-04103 Leipzig, Germany
| | - Jessica Hübner
- Computational EvoDevo Group, Institute for Computer Science, Leipzig University, Härtelstr. 16-18, 04109 Leipzig, Germany
| | - Heike Betat
- Institute for Biochemistry, Leipzig University, Brüderstraße 34, D-04103 Leipzig, Germany
| | - Sonja Prohaska
- Computational EvoDevo Group, Institute for Computer Science, Leipzig University, Härtelstr. 16-18, 04109 Leipzig, Germany,Interdisciplinary Centre for Bioinformatics, Leipzig University, Härtelstr. 16-18, 04109 Leipzig, Germany,Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 87501, USA,Complexity Science Hub Vienna, Josefstädter Str. 39, 1080 Wien, Austria
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3
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de Wijn R, Rollet K, Ernst FGM, Wellner K, Betat H, Mörl M, Sauter C. CCA-addition in the cold: Structural characterization of the psychrophilic CCA-adding enzyme from the permafrost bacterium Planococcus halocryophilus. Comput Struct Biotechnol J 2021; 19:5845-5855. [PMID: 34765099 PMCID: PMC8563995 DOI: 10.1016/j.csbj.2021.10.018] [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: 06/14/2021] [Revised: 10/12/2021] [Accepted: 10/12/2021] [Indexed: 11/25/2022] Open
Abstract
A high-resolution structure of a psychrophilic RNA polymerase contributes to our knowledge of cold adaptation. While catalytic core motifs are conserved, at least one shows cold adaptation. Loss of helix-capping increases structural flexibility in a catalytic core motif. Overall reduction of alpha-helical elements appears as a strategy for cold adaptation.
CCA-adding enzymes are highly specific RNA polymerases that add and maintain the sequence C-C-A at tRNA 3‘-ends. Recently, we could reveal that cold adaptation of such a polymerase is not only achieved at the expense of enzyme stability, but also at the cost of polymerization fidelity. Enzymes from psychrophilic organisms usually show an increased structural flexibility to enable catalysis at low temperatures. Here, polymerases face a dilemma, as there is a discrepancy between the need for a tightly controlled flexibility during polymerization and an increased flexibility as strategy for cold adaptation. Based on structural and biochemical analyses, we contribute to clarify the cold adaptation strategy of the psychrophilic CCA-adding enzyme from Planococcus halocryophilus, a gram-positive bacterium thriving in the arctic permafrost at low temperatures down to −15 °C. A comparison with the closely related enzyme from the thermophilic bacterium Geobacillus stearothermophilus reveals several features of cold adaptation - a significantly reduced amount of alpha-helical elements in the C-terminal tRNA-binding region and a structural adaptation in one of the highly conserved catalytic core motifs located in the N-terminal catalytic core of the enzyme.
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Affiliation(s)
- Raphaël de Wijn
- Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC, 67084 Strasbourg, France
| | - Kévin Rollet
- Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC, 67084 Strasbourg, France.,Institute for Biochemistry, Leipzig University, Brüderstr. 34, 04103 Leipzig, Germany
| | - Felix G M Ernst
- Institute for Biochemistry, Leipzig University, Brüderstr. 34, 04103 Leipzig, Germany
| | - Karolin Wellner
- Institute for Biochemistry, Leipzig University, Brüderstr. 34, 04103 Leipzig, Germany
| | - Heike Betat
- Institute for Biochemistry, Leipzig University, Brüderstr. 34, 04103 Leipzig, Germany
| | - Mario Mörl
- Institute for Biochemistry, Leipzig University, Brüderstr. 34, 04103 Leipzig, Germany
| | - Claude Sauter
- Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC, 67084 Strasbourg, France
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4
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Erber L, Betat H, Mörl M. CCA-Addition Gone Wild: Unusual Occurrence and Phylogeny of Four Different tRNA Nucleotidyltransferases in Acanthamoeba castellanii. Mol Biol Evol 2021; 38:1006-1017. [PMID: 33095240 PMCID: PMC7947759 DOI: 10.1093/molbev/msaa270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
tRNAs are important players in the protein synthesis machinery, where they act as adapter molecules for translating the mRNA codons into the corresponding amino acid sequence. In a series of highly conserved maturation steps, the primary transcripts are converted into mature tRNAs. In the amoebozoan Acanthamoeba castellanii, a highly unusual evolution of some of these processing steps was identified that are based on unconventional RNA polymerase activities. In this context, we investigated the synthesis of the 3′-terminal CCA-end that is added posttranscriptionally by a specialized polymerase, the tRNA nucleotidyltransferase (CCA-adding enzyme). The majority of eukaryotic organisms carry only a single gene for a CCA-adding enzyme that acts on both the cytosolic and the mitochondrial tRNA pool. In a bioinformatic analysis of the genome of this organism, we identified a surprising multitude of genes for enzymes that contain the active site signature of eukaryotic/eubacterial tRNA nucleotidyltransferases. In vitro activity analyses of these enzymes revealed that two proteins represent bona fide CCA-adding enzymes, one of them carrying an N-terminal sequence corresponding to a putative mitochondrial target signal. The other enzymes have restricted activities and represent CC- and A-adding enzymes, respectively. The A-adding enzyme is of particular interest, as its sequence is closely related to corresponding enzymes from Proteobacteria, indicating a horizontal gene transfer. Interestingly, this unusual diversity of nucleotidyltransferase genes is not restricted to Acanthamoeba castellanii but is also present in other members of the Acanthamoeba genus, indicating an ancient evolutionary trait.
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Affiliation(s)
- Lieselotte Erber
- Institute for Biochemistry, Leipzig University, Leipzig, Germany
| | - Heike Betat
- Institute for Biochemistry, Leipzig University, Leipzig, Germany
| | - Mario Mörl
- Institute for Biochemistry, Leipzig University, Leipzig, Germany
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5
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Hennig O, Philipp S, Bonin S, Rollet K, Kolberg T, Jühling T, Betat H, Sauter C, Mörl M. Adaptation of the Romanomermis culicivorax CCA-Adding Enzyme to Miniaturized Armless tRNA Substrates. Int J Mol Sci 2020; 21:E9047. [PMID: 33260740 PMCID: PMC7730189 DOI: 10.3390/ijms21239047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 11/25/2020] [Indexed: 11/17/2022] Open
Abstract
The mitochondrial genome of the nematode Romanomermis culicivorax encodes for miniaturized hairpin-like tRNA molecules that lack D- as well as T-arms, strongly deviating from the consensus cloverleaf. The single tRNA nucleotidyltransferase of this organism is fully active on armless tRNAs, while the human counterpart is not able to add a complete CCA-end. Transplanting single regions of the Romanomermis enzyme into the human counterpart, we identified a beta-turn element of the catalytic core that-when inserted into the human enzyme-confers full CCA-adding activity on armless tRNAs. This region, originally identified to position the 3'-end of the tRNA primer in the catalytic core, dramatically increases the enzyme's substrate affinity. While conventional tRNA substrates bind to the enzyme by interactions with the T-arm, this is not possible in the case of armless tRNAs, and the strong contribution of the beta-turn compensates for an otherwise too weak interaction required for the addition of a complete CCA-terminus. This compensation demonstrates the remarkable evolutionary plasticity of the catalytic core elements of this enzyme to adapt to unconventional tRNA substrates.
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Affiliation(s)
- Oliver Hennig
- Institute for Biochemistry, Leipzig University, Brüderstraße 34, 04103 Leipzig, Germany; (O.H.); (S.P.); (S.B.); (K.R.); (T.K.); (T.J.); (H.B.)
| | - Susanne Philipp
- Institute for Biochemistry, Leipzig University, Brüderstraße 34, 04103 Leipzig, Germany; (O.H.); (S.P.); (S.B.); (K.R.); (T.K.); (T.J.); (H.B.)
| | - Sonja Bonin
- Institute for Biochemistry, Leipzig University, Brüderstraße 34, 04103 Leipzig, Germany; (O.H.); (S.P.); (S.B.); (K.R.); (T.K.); (T.J.); (H.B.)
| | - Kévin Rollet
- Institute for Biochemistry, Leipzig University, Brüderstraße 34, 04103 Leipzig, Germany; (O.H.); (S.P.); (S.B.); (K.R.); (T.K.); (T.J.); (H.B.)
- Architecture et Réactivité de l’ARN, Université de Strasbourg, CNRS, IBMC, 67084 Strasbourg, France;
| | - Tim Kolberg
- Institute for Biochemistry, Leipzig University, Brüderstraße 34, 04103 Leipzig, Germany; (O.H.); (S.P.); (S.B.); (K.R.); (T.K.); (T.J.); (H.B.)
| | - Tina Jühling
- Institute for Biochemistry, Leipzig University, Brüderstraße 34, 04103 Leipzig, Germany; (O.H.); (S.P.); (S.B.); (K.R.); (T.K.); (T.J.); (H.B.)
- Architecture et Réactivité de l’ARN, Université de Strasbourg, CNRS, IBMC, 67084 Strasbourg, France;
| | - Heike Betat
- Institute for Biochemistry, Leipzig University, Brüderstraße 34, 04103 Leipzig, Germany; (O.H.); (S.P.); (S.B.); (K.R.); (T.K.); (T.J.); (H.B.)
| | - Claude Sauter
- Architecture et Réactivité de l’ARN, Université de Strasbourg, CNRS, IBMC, 67084 Strasbourg, France;
| | - Mario Mörl
- Institute for Biochemistry, Leipzig University, Brüderstraße 34, 04103 Leipzig, Germany; (O.H.); (S.P.); (S.B.); (K.R.); (T.K.); (T.J.); (H.B.)
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6
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Erber L, Franz P, Betat H, Prohaska S, Mörl M. Divergent Evolution of Eukaryotic CC- and A-Adding Enzymes. Int J Mol Sci 2020; 21:ijms21020462. [PMID: 31936900 PMCID: PMC7014341 DOI: 10.3390/ijms21020462] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 01/06/2020] [Accepted: 01/09/2020] [Indexed: 12/04/2022] Open
Abstract
Synthesis of the CCA end of essential tRNAs is performed either by CCA-adding enzymes or as a collaboration between enzymes restricted to CC- and A-incorporation. While the occurrence of such tRNA nucleotidyltransferases with partial activities seemed to be restricted to Bacteria, the first example of such split CCA-adding activities was reported in Schizosaccharomyces pombe. Here, we demonstrate that the choanoflagellate Salpingoeca rosetta also carries CC- and A-adding enzymes. However, these enzymes have distinct evolutionary origins. Furthermore, the restricted activity of the eukaryotic CC-adding enzymes has evolved in a different way compared to their bacterial counterparts. Yet, the molecular basis is very similar, as highly conserved positions within a catalytically important flexible loop region are missing in the CC-adding enzymes. For both the CC-adding enzymes from S. rosetta as well as S. pombe, introduction of the loop elements from closely related enzymes with full activity was able to restore CCA-addition, corroborating the significance of this loop in the evolution of bacterial as well as eukaryotic tRNA nucleotidyltransferases. Our data demonstrate that partial CC- and A-adding activities in Bacteria and Eukaryotes are based on the same mechanistic principles but, surprisingly, originate from different evolutionary events.
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Affiliation(s)
- Lieselotte Erber
- Institute for Biochemistry, Leipzig University, Brüderstraße 34, 04103 Leipzig, Germany; (L.E.); (P.F.); (H.B.)
| | - Paul Franz
- Institute for Biochemistry, Leipzig University, Brüderstraße 34, 04103 Leipzig, Germany; (L.E.); (P.F.); (H.B.)
| | - Heike Betat
- Institute for Biochemistry, Leipzig University, Brüderstraße 34, 04103 Leipzig, Germany; (L.E.); (P.F.); (H.B.)
| | - Sonja Prohaska
- Computational EvoDevo Group, Department of Computer Science, Leipzig University, Härtelstraße 16-18, 04107 Leipzig, Germany;
- Interdisciplinary Center for Bioinformatics, Leipzig University, Härtelstraße 16-18, 04107 Leipzig, Germany
- Santa Fe Institute for Complex Systems, 1399 Hyde Park Road, Santa Fe, NM 87501, USA
| | - Mario Mörl
- Institute for Biochemistry, Leipzig University, Brüderstraße 34, 04103 Leipzig, Germany; (L.E.); (P.F.); (H.B.)
- Correspondence: ; Tel.: +49-341-9736-911; Fax: +49-341-9736-919
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7
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Phylogeny and Evolution of RNA 3'-Nucleotidyltransferases in Bacteria. J Mol Evol 2019; 87:254-270. [PMID: 31435688 DOI: 10.1007/s00239-019-09907-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 08/07/2019] [Indexed: 10/26/2022]
Abstract
The tRNA nucleotidyltransferases and poly(A) polymerases belong to a superfamily of nucleotidyltransferases. The amino acid sequences of a number of bacterial tRNA nucleotidyltransferases and poly(A) polymerases have been used to construct a rooted, neighbor-joining phylogenetic tree. Using information gleaned from that analysis, along with data from the rRNA-based phylogenetic tree, structural data available on a number of members of the superfamily and other biochemical information on the superfamily, it is possible to suggest a scheme for the evolution of the bacterial tRNA nucleotidyltransferases and poly(A) polymerases from ancestral species. Elements of that scheme are discussed along with questions arising from the scheme which can be explored experimentally.
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8
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Wellner K, Pöhler MT, Betat H, Mörl M. Dual expression of CCA-adding enzyme and RNase T in Escherichia coli generates a distinct cca growth phenotype with diverse applications. Nucleic Acids Res 2019; 47:3631-3639. [PMID: 30828718 PMCID: PMC6468291 DOI: 10.1093/nar/gkz133] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 02/14/2019] [Accepted: 02/18/2019] [Indexed: 11/22/2022] Open
Abstract
Correct synthesis and maintenance of functional tRNA 3′-CCA-ends is a crucial prerequisite for aminoacylation and must be achieved by the phylogenetically diverse group of tRNA nucleotidyltransferases. While numerous reports on the in vitro characterization exist, robust analysis under in vivo conditions is lacking. Here, we utilize Escherichia coli RNase T, a tRNA-processing enzyme responsible for the tRNA-CCA-end turnover, to generate an in vivo system for the evaluation of A-adding activity. Expression of RNase T results in a prominent growth phenotype that renders the presence of a CCA- or A-adding enzyme essential for cell survival in an E. coli Δcca background. The distinct growth fitness allows for both complementation and selection of enzyme variants in a natural environment. We demonstrate the potential of our system via detection of altered catalytic efficiency and temperature sensitivity. Furthermore, we select functional enzyme variants out of a sequence pool carrying a randomized codon for a highly conserved position essential for catalysis. The presented E. coli-based approach opens up a wide field of future studies including the investigation of tRNA nucleotidyltransferases from all domains of life and the biological relevance of in vitro data concerning their functionality and mode of operation.
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Affiliation(s)
- Karolin Wellner
- Institute for Biochemistry, Leipzig University, Brüderstr. 34, 04103 Leipzig, Germany
| | - Marie-Theres Pöhler
- Institute for Biochemistry, Leipzig University, Brüderstr. 34, 04103 Leipzig, Germany
| | - Heike Betat
- Institute for Biochemistry, Leipzig University, Brüderstr. 34, 04103 Leipzig, Germany
| | - Mario Mörl
- Institute for Biochemistry, Leipzig University, Brüderstr. 34, 04103 Leipzig, Germany
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9
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Leibovitch M, Hanic-Joyce PJ, Joyce PBM. In vitro studies of disease-linked variants of human tRNA nucleotidyltransferase reveal decreased thermal stability and altered catalytic activity. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2018; 1866:527-540. [PMID: 29454993 DOI: 10.1016/j.bbapap.2018.02.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 02/09/2018] [Accepted: 02/14/2018] [Indexed: 11/15/2022]
Abstract
Mutations in the human TRNT1 gene encoding tRNA nucleotidyltransferase (tRNA-NT), an essential enzyme responsible for addition of the CCA (cytidine-cytidine-adenosine) sequence to the 3'-termini of tRNAs, have been linked to disease phenotypes including congenital sideroblastic anemia with B-cell immunodeficiency, periodic fevers and developmental delay (SIFD) or retinitis pigmentosa with erythrocyte microcytosis. The effects of these disease-linked mutations on the structure and function of tRNA-NT have not been explored. Here we use biochemical and biophysical approaches to study how five SIFD-linked amino acid substitutions (T154I, M158V, L166S, R190I and I223T), residing in the N-terminal head and neck domains of the enzyme, affect the structure and activity of human tRNA-NT in vitro. Our data suggest that the SIFD phenotype is linked to poor stability of the T154I and L166S variant proteins, and to a combination of reduced stability and altered catalytic efficiency in the M158 V, R190I and I223T variants.
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Affiliation(s)
- M Leibovitch
- Department of Chemistry and Biochemistry and Centre for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke St. W., Montréal H4B 1R6, Québec, Canada
| | - P J Hanic-Joyce
- Department of Chemistry and Biochemistry and Centre for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke St. W., Montréal H4B 1R6, Québec, Canada
| | - P B M Joyce
- Department of Chemistry and Biochemistry and Centre for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke St. W., Montréal H4B 1R6, Québec, Canada.
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10
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Ernst FGM, Erber L, Sammler J, Jühling F, Betat H, Mörl M. Cold adaptation of tRNA nucleotidyltransferases: A tradeoff in activity, stability and fidelity. RNA Biol 2017; 15:144-155. [PMID: 29099323 DOI: 10.1080/15476286.2017.1391445] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
Cold adaptation is an evolutionary process that has dramatic impact on enzymatic activity. Increased flexibility of the protein structure represents the main evolutionary strategy for efficient catalysis and reaction rates in the cold, but is achieved at the expense of structural stability. This results in a significant activity-stability tradeoff, as it was observed for several metabolic enzymes. In polymerases, however, not only reaction rates, but also fidelity plays an important role, as these enzymes have to synthesize copies of DNA and RNA as exact as possible. Here, we investigate the effects of cold adaptation on the highly accurate CCA-adding enzyme, an RNA polymerase that uses an internal amino acid motif within the flexible catalytic core as a template to synthesize the CCA triplet at tRNA 3'-ends. As the relative orientation of these residues determines nucleotide selection, we characterized how cold adaptation impacts template reading and fidelity. In a comparative analysis of closely related psychro-, meso-, and thermophilic enzymes, the cold-adapted polymerase shows a remarkable error rate during CCA synthesis in vitro as well as in vivo. Accordingly, CCA-adding activity at low temperatures is not only achieved at the expense of structural stability, but also results in a reduced polymerization fidelity.
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Affiliation(s)
- Felix G M Ernst
- a Institute for Biochemistry, University of Leipzig , Leipzig , Germany
| | - Lieselotte Erber
- a Institute for Biochemistry, University of Leipzig , Leipzig , Germany
| | - Joana Sammler
- a Institute for Biochemistry, University of Leipzig , Leipzig , Germany
| | - Frank Jühling
- b INSERM Unit 1110 , Institute of Viral and Liver Diseases, University of Strasbourg , Strasbourg , France
| | - Heike Betat
- a Institute for Biochemistry, University of Leipzig , Leipzig , Germany
| | - Mario Mörl
- a Institute for Biochemistry, University of Leipzig , Leipzig , Germany
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11
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Franz P, Betat H, Mörl M. Genotyping bacterial and fungal pathogens using sequence variation in the gene for the CCA-adding enzyme. BMC Microbiol 2016; 16:47. [PMID: 26987313 PMCID: PMC4797355 DOI: 10.1186/s12866-016-0670-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 03/09/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND To allow an immediate treatment of an infection with suitable antibiotics and bactericides or fungicides, there is an urgent need for fast and precise identification of the causative human pathogens. Methods based on DNA sequence comparison like 16S rRNA analysis have become standard tools for pathogen verification. However, the distinction of closely related organisms remains a challenging task. To overcome such limitations, we identified a new genomic target sequence located in the single copy gene for tRNA nucleotidyltransferase fulfilling the requirements for a ubiquitous, yet highly specific DNA marker. In the present study, we demonstrate that this sequence marker has a higher discriminating potential than commonly used genotyping markers in pro- as well as eukaryotes, underscoring its applicability as an excellent diagnostic tool in infectology. RESULTS Based on phylogenetic analyses, a region within the gene for tRNA nucleotidyltransferase (CCA-adding enzyme) was identified as highly heterogeneous. As prominent examples for pro- and eukaryotic pathogens, several Vibrio and Aspergillus species were used for genotyping and identification in a multiplex PCR approach followed by gel electrophoresis and fluorescence-based product detection. Compared to rRNA analysis, the selected gene region of the tRNA nucleotidyltransferase revealed a seven to 30-fold higher distinction potential between closely related Vibrio or Aspergillus species, respectively. The obtained data exhibit a superb genome specificity in the diagnostic analysis. Even in the presence of a 1,000-fold excess of human genomic DNA, no unspecific amplicons were produced. CONCLUSIONS These results indicate that a relatively short segment of the coding region for tRNA nucleotidyltransferase has a higher discriminatory potential than most established diagnostic DNA markers. Besides identifying microbial pathogens in infections, further possible applications of this new marker are food hygiene controls or metagenome analyses.
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Affiliation(s)
- Paul Franz
- Institute for Biochemistry, Leipzig University, Brüderstr. 34, 04103, Leipzig, Germany
| | - Heike Betat
- Institute for Biochemistry, Leipzig University, Brüderstr. 34, 04103, Leipzig, Germany
| | - Mario Mörl
- Institute for Biochemistry, Leipzig University, Brüderstr. 34, 04103, Leipzig, Germany
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12
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Betat H, Mede T, Tretbar S, Steiner L, Stadler PF, Mörl M, Prohaska SJ. The ancestor of modern Holozoa acquired the CCA-adding enzyme from Alphaproteobacteria by horizontal gene transfer. Nucleic Acids Res 2015; 43:6739-46. [PMID: 26117543 PMCID: PMC4538823 DOI: 10.1093/nar/gkv631] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 06/07/2015] [Indexed: 12/03/2022] Open
Abstract
Transfer RNAs (tRNAs) require the absolutely conserved sequence motif CCA at their 3′-ends, representing the site of aminoacylation. In the majority of organisms, this trinucleotide sequence is not encoded in the genome and thus has to be added post-transcriptionally by the CCA-adding enzyme, a specialized nucleotidyltransferase. In eukaryotic genomes this ubiquitous and highly conserved enzyme family is usually represented by a single gene copy. Analysis of published sequence data allows us to pin down the unusual evolution of eukaryotic CCA-adding enzymes. We show that the CCA-adding enzymes of animals originated from a horizontal gene transfer event in the stem lineage of Holozoa, i.e. Metazoa (animals) and their unicellular relatives, the Choanozoa. The tRNA nucleotidyltransferase, acquired from an α-proteobacterium, replaced the ancestral enzyme in Metazoa. However, in Choanoflagellata, the group of Choanozoa that is closest to Metazoa, both the ancestral and the horizontally transferred CCA-adding enzymes have survived. Furthermore, our data refute a mitochondrial origin of the animal tRNA nucleotidyltransferases.
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Affiliation(s)
- Heike Betat
- Institute for Biochemistry, University of Leipzig, Brüderstraße 34, D-04103 Leipzig, Germany
| | - Tobias Mede
- Computational EvoDevo Group, Department of Computer Science, University of Leipzig, Härtelstraße 16-18, D-04107 Leipzig, Germany
| | - Sandy Tretbar
- Institute for Biochemistry, University of Leipzig, Brüderstraße 34, D-04103 Leipzig, Germany
| | - Lydia Steiner
- Computational EvoDevo Group, Department of Computer Science, University of Leipzig, Härtelstraße 16-18, D-04107 Leipzig, Germany
| | - Peter F Stadler
- Bioinformatics Group, Department of Computer Science, University of Leipzig, Härtelstraße 16-18, D-04107 Leipzig, Germany Interdisciplinary Center for Bioinformatics, University of Leipzig, Härtelstraße 16-18, D-04107 Leipzig, Germany Max-Planck-Institute for Mathematics in the Sciences, Inselstraße 22, D-04103 Leipzig, Germany Fraunhofer Institut für Zelltherapie und Immunologie, Perlickstraße 1, D-04103 Leipzig, Germany Department of Theoretical Chemistry, University of Vienna, Währingerstraße 17, A-1090 Wien, Austria Center for non-coding RNA in Technology and Health, University of Copenhagen, Grønnegårdsvej 3, DK-1870 Frederiksberg, Denmark Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 87501, USA
| | - Mario Mörl
- Institute for Biochemistry, University of Leipzig, Brüderstraße 34, D-04103 Leipzig, Germany
| | - Sonja J Prohaska
- Computational EvoDevo Group, Department of Computer Science, University of Leipzig, Härtelstraße 16-18, D-04107 Leipzig, Germany Interdisciplinary Center for Bioinformatics, University of Leipzig, Härtelstraße 16-18, D-04107 Leipzig, Germany
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13
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Wende S, Bonin S, Götze O, Betat H, Mörl M. The identity of the discriminator base has an impact on CCA addition. Nucleic Acids Res 2015; 43:5617-29. [PMID: 25958396 PMCID: PMC4477674 DOI: 10.1093/nar/gkv471] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 04/29/2015] [Indexed: 11/13/2022] Open
Abstract
CCA-adding enzymes synthesize and maintain the C-C-A sequence at the tRNA 3'-end, generating the attachment site for amino acids. While tRNAs are the most prominent substrates for this polymerase, CCA additions on non-tRNA transcripts are described as well. To identify general features for substrate requirement, a pool of randomized transcripts was incubated with the human CCA-adding enzyme. Most of the RNAs accepted for CCA addition carry an acceptor stem-like terminal structure, consistent with tRNA as the main substrate group for this enzyme. While these RNAs show no sequence conservation, the position upstream of the CCA end was in most cases represented by an adenosine residue. In tRNA, this position is described as discriminator base, an important identity element for correct aminoacylation. Mutational analysis of the impact of the discriminator identity on CCA addition revealed that purine bases (with a preference for adenosine) are strongly favoured over pyrimidines. Furthermore, depending on the tRNA context, a cytosine discriminator can cause a dramatic number of misincorporations during CCA addition. The data correlate with a high frequency of adenosine residues at the discriminator position observed in vivo. Originally identified as a prominent identity element for aminoacylation, this position represents a likewise important element for efficient and accurate CCA addition.
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Affiliation(s)
- Sandra Wende
- Institute for Biochemistry, University of Leipzig, Brüderstrasse 34, 04103 Leipzig, Germany
| | - Sonja Bonin
- Institute for Biochemistry, University of Leipzig, Brüderstrasse 34, 04103 Leipzig, Germany
| | - Oskar Götze
- Institute for Biochemistry, University of Leipzig, Brüderstrasse 34, 04103 Leipzig, Germany
| | - Heike Betat
- Institute for Biochemistry, University of Leipzig, Brüderstrasse 34, 04103 Leipzig, Germany
| | - Mario Mörl
- Institute for Biochemistry, University of Leipzig, Brüderstrasse 34, 04103 Leipzig, Germany
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14
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Yamashita S, Martinez A, Tomita K. Measurement of Acceptor-TΨC Helix Length of tRNA for Terminal A76-Addition by A-Adding Enzyme. Structure 2015; 23:830-842. [PMID: 25914059 DOI: 10.1016/j.str.2015.03.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 02/25/2015] [Accepted: 03/23/2015] [Indexed: 11/25/2022]
Abstract
The 3'-terminal CCA (C74C75A76-3') of tRNA is required for protein synthesis. In Aquifex aeolicus, the CCA-3' is synthesized by CC-adding and A-adding enzymes, although in most organisms, CCA is synthesized by a single CCA-adding enzyme. The mechanisms by which the A-adding enzyme adds only A76, but not C74C75, onto tRNA remained elusive. The complex structures of the enzyme with various tRNAs revealed the presence of a single tRNA binding site on the enzyme, with the enzyme measuring the acceptor-TΨC helix length of tRNA. The 3'-C75 of tRNA lacking A76 can reach the active site and the size and shape of the nucleotide binding pocket at the insertion stage are suitable for ATP. The 3'-C74 of tRNA lacking C75A76 cannot reach the active site, although CTP or ATP can bind the active pocket. Thus, the A-adding enzyme adds only A76, but not C74C75, onto tRNA.
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Affiliation(s)
- Seisuke Yamashita
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1, Higashi, Tsukuba, Ibaraki 305-8566, Japan
| | - Anna Martinez
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1, Higashi, Tsukuba, Ibaraki 305-8566, Japan
| | - Kozo Tomita
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1, Higashi, Tsukuba, Ibaraki 305-8566, Japan.
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15
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Ernst FGM, Rickert C, Bluschke A, Betat H, Steinhoff HJ, Mörl M. Domain movements during CCA-addition: a new function for motif C in the catalytic core of the human tRNA nucleotidyltransferases. RNA Biol 2015; 12:435-46. [PMID: 25849199 PMCID: PMC4615804 DOI: 10.1080/15476286.2015.1018502] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 02/06/2015] [Accepted: 02/07/2015] [Indexed: 10/23/2022] Open
Abstract
CCA-adding enzymes are highly specific RNA polymerases that synthesize and maintain the sequence CCA at the tRNA 3'-end. This nucleotide triplet is a prerequisite for tRNAs to be aminoacylated and to participate in protein biosynthesis. During CCA-addition, a set of highly conserved motifs in the catalytic core of these enzymes is responsible for accurate sequential nucleotide incorporation. In the nucleotide binding pocket, three amino acid residues form Watson-Crick-like base pairs to the incoming CTP and ATP. A reorientation of these templating amino acids switches the enzyme's specificity from CTP to ATP recognition. However, the mechanism underlying this essential structural rearrangement is not understood. Here, we show that motif C, whose actual function has not been identified yet, contributes to the switch in nucleotide specificity during polymerization. Biochemical characterization as well as EPR spectroscopy measurements of the human enzyme reveal that mutating the highly conserved amino acid position D139 in this motif interferes with AMP incorporation and affects interdomain movements in the enzyme. We propose a model of action, where motif C forms a flexible spring element modulating the relative orientation of the enzyme's head and body domains to accommodate the growing 3'-end of the tRNA. Furthermore, these conformational transitions initiate the rearranging of the templating amino acids to switch the specificity of the nucleotide binding pocket from CTP to ATP during CCA-synthesis.
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Affiliation(s)
- Felix G M Ernst
- Institute for Biochemistry; University of Leipzig; Leipzig, Germany
| | | | | | - Heike Betat
- Institute for Biochemistry; University of Leipzig; Leipzig, Germany
| | | | - Mario Mörl
- Institute for Biochemistry; University of Leipzig; Leipzig, Germany
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16
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Goring ME, Leibovitch M, Gea-Mallorqui E, Karls S, Richard F, Hanic-Joyce PJ, Joyce PBM. The ability of an arginine to tryptophan substitution in Saccharomyces cerevisiae tRNA nucleotidyltransferase to alleviate a temperature-sensitive phenotype suggests a role for motif C in active site organization. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2013; 1834:2097-106. [PMID: 23872483 DOI: 10.1016/j.bbapap.2013.07.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 07/08/2013] [Accepted: 07/10/2013] [Indexed: 11/15/2022]
Abstract
We report that the temperature-sensitive (ts) phenotype in Saccharomyces cerevisiae associated with a variant tRNA nucleotidyltransferase containing an amino acid substitution at position 189 results from a reduced ability to incorporate AMP and CMP into tRNAs. We show that this defect can be compensated for by a second-site suppressor converting residue arginine 64 to tryptophan. The R64W substitution does not alter the structure or thermal stability of the enzyme dramatically but restores catalytic activity in vitro and suppresses the ts phenotype in vivo. R64 is found in motif A known to be involved in catalysis and nucleotide triphosphate binding while E189 lies within motif C previously thought only to connect the head and neck domains of the protein. Although mutagenesis experiments indicate that residues R64 and E189 do not interact directly, our data suggest a critical role for residue E189 in enzyme structure and function. Both R64 and E189 may contribute to the organization of the catalytic domain of the enzyme. These results, along with overexpression and deletion analyses, show that the ts phenotype of cca1-E189F does not arise from thermal instability of the variant tRNA nucleotidyltransferase but instead from the inability of a partially active enzyme to support growth only at higher temperatures.
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Affiliation(s)
- Mark E Goring
- Department of Biology, Concordia University, Montréal, H4B 1R6, Canada
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17
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An inhibitory C-terminal region dictates the specificity of A-adding enzymes. Proc Natl Acad Sci U S A 2011; 108:21040-5. [PMID: 22167803 DOI: 10.1073/pnas.1116117108] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
For efficient aminoacylation, tRNAs carry the conserved 3'-terminal sequence C-C-A, which is synthesized by highly specific tRNA nucleotidyltransferases (CCA-adding enzymes). In several prokaryotes, this function is accomplished by separate enzymes for CC- and A-addition. As A-adding enzymes carry an N-terminal catalytic core identical to that of CCA-adding enzymes, it is unclear why their activity is restricted. Here, it is shown that C-terminal deletion variants of A-adding enzymes acquire full and precise CCA-incorporating activity. The deleted region seems to be responsible for tRNA primer selection, restricting the enzyme's specificity to tRNAs ending with CC. The data suggest that A-adding enzymes carry an intrinsic CCA-adding activity that can be reactivated by the introduction of deletions in the C-terminal domain. Furthermore, a unique subtype of CCA-adding enzymes could be identified that evolved out of A-adding enzymes, suggesting that mutations and deletions in nucleotidyltransferases can lead to altered and even more complex activities, as a simple A-incorporation is converted into sequence-specific addition of C and A residues. Such activity-modifying events may have had an important role in the evolution of tRNA nucleotidyltransferases.
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