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Onoguchi M, Otsuka R, Koyama M, Ando T, Mutsuro-Aoki H, Umehara T, Tamura K. Elucidation of productive alanine recognition mechanism by Escherichia coli alanyl-tRNA synthetase. Biosystems 2024; 237:105152. [PMID: 38346553 DOI: 10.1016/j.biosystems.2024.105152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 02/08/2024] [Accepted: 02/09/2024] [Indexed: 02/22/2024]
Abstract
Alanyl-tRNA synthetase (AlaRS) incorrectly recognizes both a slightly smaller glycine and a slightly larger serine in addition to alanine, and the probability of incorrect identification is extremely low at 1/300 and 1/170, respectively. Alanine is the second smallest amino acid after glycine; however, the mechanism by which AlaRS specifically identifies small differences in side chains with high accuracy remains unknown. In this study, using a malachite green assay, we aimed to elucidate the alanine recognition mechanism of a fragment (AlaRS368N) containing only the amino acid activation domain of Escherichia coli AlaRS. This method quantifies monophosphate by decomposing pyrophosphate generated during aminoacyl-AMP production. AlaRS368N produced far more pyrophosphate when glycine or serine was used as a substrate than when alanine was used. Among several mutants tested, an AlaRS mutant in which the widely conserved aspartic acid at the 235th position (D235) near the active center was replaced with glutamic acid (D235E) increased pyrophosphate release for the alanine substrate, compared to that from glycine and serine. These results suggested that D235 is optimal for AlaRS to specifically recognize alanine. Alanylation activities of an RNA minihelix by the mutants of valine at the 214th position (V214) of another fragment (AlaRS442N), which is the smallest AlaRS with alanine charging activity, suggest the existence of the van der Waals-like interaction between the side chain of V214 and the methyl group of the alanine substrate.
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Affiliation(s)
- Mayu Onoguchi
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan
| | - Riku Otsuka
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan
| | - Miki Koyama
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan
| | - Tadashi Ando
- Department of Applied Electronics, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan; Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Hiromi Mutsuro-Aoki
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan
| | - Takuya Umehara
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan
| | - Koji Tamura
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan; Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
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Carter CW. Base Pairing Promoted the Self-Organization of Genetic Coding, Catalysis, and Free-Energy Transduction. Life (Basel) 2024; 14:199. [PMID: 38398709 PMCID: PMC10890426 DOI: 10.3390/life14020199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 01/21/2024] [Accepted: 01/25/2024] [Indexed: 02/25/2024] Open
Abstract
How Nature discovered genetic coding is a largely ignored question, yet the answer is key to explaining the transition from biochemical building blocks to life. Other, related puzzles also fall inside the aegis enclosing the codes themselves. The peptide bond is unstable with respect to hydrolysis. So, it requires some form of chemical free energy to drive it. Amino acid activation and acyl transfer are also slow and must be catalyzed. All living things must thus also convert free energy and synchronize cellular chemistry. Most importantly, functional proteins occupy only small, isolated regions of sequence space. Nature evolved heritable symbolic data processing to seek out and use those sequences. That system has three parts: a memory of how amino acids behave in solution and inside proteins, a set of code keys to access that memory, and a scoring function. The code keys themselves are the genes for cognate pairs of tRNA and aminoacyl-tRNA synthetases, AARSs. The scoring function is the enzymatic specificity constant, kcat/kM, which measures both catalysis and specificity. The work described here deepens the evidence for and understanding of an unexpected consequence of ancestral bidirectional coding. Secondary structures occur in approximately the same places within antiparallel alignments of their gene products. However, the polar amino acids that define the molecular surface of one are reflected into core-defining non-polar side chains on the other. Proteins translated from base-paired coding strands fold up inside out. Bidirectional genes thus project an inverted structural duality into the proteome. I review how experimental data root the scoring functions responsible for the origins of coding and catalyzed activation of unfavorable chemical reactions in that duality.
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Affiliation(s)
- Charles W Carter
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7260, USA
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Douglas J, Bouckaert R, Carter CW, Wills P. Enzymic recognition of amino acids drove the evolution of primordial genetic codes. Nucleic Acids Res 2024; 52:558-571. [PMID: 38048305 PMCID: PMC10810186 DOI: 10.1093/nar/gkad1160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 10/28/2023] [Accepted: 11/20/2023] [Indexed: 12/06/2023] Open
Abstract
How genetic information gained its exquisite control over chemical processes needed to build living cells remains an enigma. Today, the aminoacyl-tRNA synthetases (AARS) execute the genetic codes in all living systems. But how did the AARS that emerged over three billion years ago as low-specificity, protozymic forms then spawn the full range of highly-specific enzymes that distinguish between 22 diverse amino acids? A phylogenetic reconstruction of extant AARS genes, enhanced by analysing modular acquisitions, reveals six AARS with distinct bacterial, archaeal, eukaryotic, or organellar clades, resulting in a total of 36 families of AARS catalytic domains. Small structural modules that differentiate one AARS family from another played pivotal roles in discriminating between amino acid side chains, thereby expanding the genetic code and refining its precision. The resulting model shows a tendency for less elaborate enzymes, with simpler catalytic domains, to activate amino acids that were not synthesised until later in the evolution of the code. The most probable evolutionary route for an emergent amino acid type to establish a place in the code was by recruiting older, less specific AARS, rather than adapting contemporary lineages. This process, retrofunctionalisation, differs from previously described mechanisms through which amino acids would enter the code.
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Affiliation(s)
- Jordan Douglas
- Department of Physics, The University of Auckland, New Zealand
- Centre for Computational Evolution, The University of Auckland, New Zealand
| | - Remco Bouckaert
- Centre for Computational Evolution, The University of Auckland, New Zealand
- School of Computer Science, The University of Auckland, New Zealand
| | - Charles W Carter
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, USA
| | - Peter R Wills
- Department of Physics, The University of Auckland, New Zealand
- Centre for Computational Evolution, The University of Auckland, New Zealand
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Patra SK, Douglas J, Wills PR, Bouckeart R, Betts L, Qing TG, Carter CW. Genomic database furnishes a spontaneous example of a functional Class II glycyl-tRNA synthetase urzyme. bioRxiv 2024:2024.01.11.575260. [PMID: 38260702 PMCID: PMC10802616 DOI: 10.1101/2024.01.11.575260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
The chief barrier to studies of how genetic coding emerged is the lack of experimental models for ancestral aminoacyl-tRNA synthetases (AARS). We hypothesized that conserved core catalytic sites could represent such ancestors. That hypothesis enabled engineering functional "urzymes" from TrpRS, LeuRS, and HisRS. We describe here a fourth urzyme, GlyCA, detected in an open reading frame from the genomic record of the arctic fox, Vulpes lagopus. GlyCA is homologous to a bacterial heterotetrameric Class II GlyRS-B. Alphafold2 predicted that the N-terminal 81 amino acids would adopt a 3D structure nearly identical to the HisRS urzyme (HisCA1). We expressed and purified that N-terminal segment. Enzymatic characterization revealed a robust single-turnover burst size and a catalytic rate for ATP consumption well in excess of that previously published for HisCA1. Time-dependent aminoacylation of tRNAGly proceeds at a rate consistent with that observed for amino acid activation. In fact, GlyCA is actually 35 times more active in glycine activation by ATP than the full-length GlyRS-B α-subunit dimer. ATP-dependent activation of the 20 canonical amino acids favors Class II amino acids that complement those favored by HisCA and LeuAC. These properties reinforce the notion that urzymes represent the requisite ancestral catalytic activities to implement a reduced genetic coding alphabet.
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Affiliation(s)
- Sourav Kumar Patra
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599-7260
| | - Jordan Douglas
- Department of Physics, The University of Auckland, New Zealand
- Centre for Computational Evolution, University of Auckland, New Zealand
| | - Peter R. Wills
- Department of Physics, The University of Auckland, New Zealand
| | - Remco Bouckeart
- Centre for Computational Evolution, University of Auckland, New Zealand
- Department of Computer Science, The University of Auckland, New Zealand
| | - Laurie Betts
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599-7260
| | | | - Charles W. Carter
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599-7260
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Tang GQ, Elder JJH, Douglas J, Carter CW. Domain acquisition by class I aminoacyl-tRNA synthetase urzymes coordinated the catalytic functions of HVGH and KMSKS motifs. Nucleic Acids Res 2023; 51:8070-8084. [PMID: 37470821 PMCID: PMC10450160 DOI: 10.1093/nar/gkad590] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 06/23/2023] [Accepted: 07/11/2023] [Indexed: 07/21/2023] Open
Abstract
Leucyl-tRNA synthetase (LeuRS) is a Class I aminoacyl-tRNA synthetase (aaRS) that synthesizes leucyl-tRNAleu for codon-directed protein synthesis. Two signature sequences, HxGH and KMSKS help stabilize transition-states for amino acid activation and tRNA aminoacylation by all Class I aaRS. Separate alanine mutants of each signature, together with the double mutant, behave in opposite ways in Pyrococcus horikoshii LeuRS and the 129-residue urzyme ancestral model generated from it (LeuAC). Free energy coupling terms, Δ(ΔG‡), for both reactions are large and favourable for LeuRS, but unfavourable for LeuAC. Single turnover assays with 32Pα-ATP show correspondingly different internal products. These results implicate domain motion in catalysis by full-length LeuRS. The distributed thermodynamic cycle of mutational changes authenticates LeuAC urzyme catalysis far more convincingly than do single point mutations. Most importantly, the evolutionary gain of function induced by acquiring the anticodon-binding (ABD) and multiple insertion modules in the catalytic domain appears to be to coordinate the catalytic function of the HxGH and KMSKS signature sequences. The implication that backbone elements of secondary structures achieve a major portion of the overall transition-state stabilization by LeuAC is also consistent with coevolution of the genetic code and metabolic pathways necessary to produce histidine and lysine sidechains.
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Affiliation(s)
- Guo Qing Tang
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599-7260, USA
| | - Jessica J H Elder
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599-7260, USA
| | - Jordan Douglas
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599-7260, USA
- Department of Physics, The University of Auckland, New Zealand
| | - Charles W Carter
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599-7260, USA
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Duan Y, Xing Y, Zhu X, Li H, Wang Y, Nan Y. Integration of transcriptomic and metabolomic reveals carbonate alkalinity stress responses in the hepatopancreas of Litopenaeus vannamei. Aquat Toxicol 2023; 260:106569. [PMID: 37207485 DOI: 10.1016/j.aquatox.2023.106569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 04/06/2023] [Accepted: 05/10/2023] [Indexed: 05/21/2023]
Abstract
Carbonate alkalinity (CA) is one of the environmental factors affecting the survival and growth of aquatic animals. However, the toxic effects of CA stress on Pacific white shrimp Litopenaeus vannamei at the molecular level are completely unclear. In this study, we investigated the changes of the survival and growth, and hepatopancreas histology of L. vannamei under different levels of CA stress, and integrated transcriptomics and metabolomics to explore major functional changes in the hepatopancreas and identify biomarkers. After CA exposure for 14 days, the survival and growth of the shrimp were reduced, and the hepatopancreas showed obvious histological damage. A total of 253 genes were differentially expressed in the three CA stress groups, and immune-related genes such as pattern recognition receptors, phenoloxidase system and detoxification metabolism were affected; substance transport-related regulators and transporters were mostly downregulated. Furthermore, the metabolic pattern of the shrimp was also altered by CA stress, especially amino acids, arachidonic acid and B-vitamin metabolites. The integration analysis of differential metabolites and genes further showed that the functions of ABC transporters, protein digestion and absorption, and amino acid biosynthesis and metabolism were highly altered by CA stress. The results of this study revealed that CA stress caused immune, substance transport, and amino acid metabolic variations in L. vannamei, and identified several potential biomarkers related to stress response.
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Affiliation(s)
- Yafei Duan
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, PR China; Key Laboratory of Efficient Utilization and Processing of Marine Fishery Resources of Hainan Province, Sanya Tropical Fisheries Research Institute, Sanya 572018, PR China; Shenzhen Base of South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shenzhen 518121, PR China.
| | - Yifu Xing
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, PR China
| | - Xuanyi Zhu
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, PR China
| | - Hua Li
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, PR China; Key Laboratory of Efficient Utilization and Processing of Marine Fishery Resources of Hainan Province, Sanya Tropical Fisheries Research Institute, Sanya 572018, PR China
| | - Yun Wang
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, PR China; Key Laboratory of Efficient Utilization and Processing of Marine Fishery Resources of Hainan Province, Sanya Tropical Fisheries Research Institute, Sanya 572018, PR China
| | - Yuxiu Nan
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, PR China
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7
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Duan Y, Xing Y, Huang J, Nan Y, Li H, Dong H. Toxicological response of Pacific white shrimp Litopenaeus vannamei to a hazardous cyanotoxin nodularin exposure. Environ Pollut 2023; 318:120950. [PMID: 36574809 DOI: 10.1016/j.envpol.2022.120950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/24/2022] [Accepted: 12/23/2022] [Indexed: 06/17/2023]
Abstract
Nodularin (NOD) is a harmful cyanotoxin that affects shrimp farming. The hepatopancreas and intestine of shrimp are the main target organs of cyanotoxins. In this study, we exposed Litopenaeus vannamei to NOD at 0.1 and 1 μg/L for 72 h, respectively, and changes in histology, oxidative stress, gene transcription, metabolism, and intestinal microbiota were investigated. After NOD exposure, the hepatopancreas and intestine showed obvious histopathological damage and elevated oxidative stress response. Transcription patterns of immune genes related to detoxification, prophenoloxidase and coagulation system were altered in the hepatopancreas. Furthermore, metabolic patterns, especially amino acid metabolism and arachidonic acid related metabolites, were also disturbed. The integration of differential genes and metabolites revealed that the functions of "alanine, aspartic acid and glutamate metabolism" and "aminoacyl-tRNA biosynthesis" were highly affected. Alternatively, NOD exposure induced the variation of the diversity and composition of intestinal microbiota, especially the abundance of potentially beneficial bacteria (Demequina, Phyllobacterium and Pseudoalteromonas) and pathogenic bacteria (Photobacterium and Vibrio). Several intestinal bacteria were correlated with the changes of host the metabolic function and immune factors. These results revealed the toxic effects of NOD on shrimp, and identified some biomarkers.
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Affiliation(s)
- Yafei Duan
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, PR China; Key Laboratory of Efficient Utilization and Processing of Marine Fishery Resources of Hainan Province, Sanya Tropical Fisheries Research Institute, Sanya 572018, PR China.
| | - Yifu Xing
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, PR China
| | - Jianhua Huang
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, PR China
| | - Yuxiu Nan
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, PR China
| | - Hua Li
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, PR China
| | - Hongbiao Dong
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, PR China
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Yi J, Cai Z, Qiu H, Lu F, Luo Z, Chen B, Gu Q, Xu J, Zhou H. Fragment screening and structural analyses highlight the ATP-assisted ligand binding for inhibitor discovery against type 1 methionyl-tRNA synthetase. Nucleic Acids Res 2022; 50:4755-4768. [PMID: 35474479 PMCID: PMC9071491 DOI: 10.1093/nar/gkac285] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 04/05/2022] [Accepted: 04/13/2022] [Indexed: 12/24/2022] Open
Abstract
Methionyl-tRNA synthetase (MetRS) charges tRNAMet with l-methionine (L-Met) to decode the ATG codon for protein translation, making it indispensable for all cellular lives. Many gram-positive bacteria use a type 1 MetRS (MetRS1), which is considered a promising antimicrobial drug target due to its low sequence identity with human cytosolic MetRS (HcMetRS, which belongs to MetRS2). Here, we report crystal structures of a representative MetRS1 from Staphylococcus aureus (SaMetRS) in its apo and substrate-binding forms. The connecting peptide (CP) domain of SaMetRS differs from HcMetRS in structural organization and dynamic movement. We screened 1049 chemical fragments against SaMetRS preincubated with or without substrate ATP, and ten hits were identified. Four cocrystal structures revealed that the fragments bound to either the L-Met binding site or an auxiliary pocket near the tRNA CCA end binding site of SaMetRS. Interestingly, fragment binding was enhanced by ATP in most cases, suggesting a potential ATP-assisted ligand binding mechanism in MetRS1. Moreover, co-binding with ATP was also observed in our cocrystal structure of SaMetRS with a class of newly reported inhibitors that simultaneously occupied the auxiliary pocket, tRNA site and L-Met site. Our findings will inspire the development of new MetRS1 inhibitors for fighting microbial infections.
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Affiliation(s)
| | | | - Haipeng Qiu
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China,Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Feihu Lu
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China,Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Zhiteng Luo
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China,Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Bingyi Chen
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China,Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Qiong Gu
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Jun Xu
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Huihao Zhou
- To whom correspondence should be addressed. Tel: +86 20 39943350;
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Hobson JJ, Li Z, Hu H, Carter CW Jr. A Leucyl-tRNA Synthetase Urzyme: Authenticity of tRNA Synthetase Catalytic Activities and Promiscuous Phosphorylation of Leucyl-5'AMP. Int J Mol Sci 2022; 23:4229. [PMID: 35457045 DOI: 10.3390/ijms23084229] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 03/30/2022] [Accepted: 03/31/2022] [Indexed: 02/05/2023] Open
Abstract
Aminoacyl-tRNA synthetase (aaRS)/tRNA cognate pairs translate the genetic code by synthesizing specific aminoacyl-tRNAs that are assembled on messenger RNA by the ribosome. Deconstruction of the two distinct aaRS superfamilies (Classes) has provided conceptual and experimental models for their early evolution. Urzymes, containing ~120–130 amino acids excerpted from regions where genetic coding sequence complementarities have been identified, are key experimental models motivated by the proposal of a single bidirectional ancestral gene. Previous reports that Class I and Class II urzymes accelerate both amino acid activation and tRNA aminoacylation have not been extended to other synthetases. We describe a third urzyme (LeuAC) prepared from the Class IA Pyrococcus horikoshii leucyl-tRNA synthetase. We adduce multiple lines of evidence for the authenticity of its catalysis of both canonical reactions, amino acid activation and tRNALeu aminoacylation. Mutation of the three active-site lysine residues to alanine causes significant, but modest reduction in both amino acid activation and aminoacylation. LeuAC also catalyzes production of ADP, a non-canonical enzymatic function that has been overlooked since it first was described for several full-length aaRS in the 1970s. Structural data suggest that the LeuAC active site accommodates two ATP conformations that are prominent in water but rarely seen bound to proteins, accounting for successive, in situ phosphorylation of the bound leucyl-5′AMP phosphate, accounting for ADP production. This unusual ATP consumption regenerates the transition state for amino acid activation and suggests, in turn, that in the absence of the editing and anticodon-binding domains, LeuAC releases leu-5′AMP unusually slowly, relative to the two phosphorylation reactions.
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Carter CW, Popinga A, Bouckaert R, Wills PR. Multidimensional Phylogenetic Metrics Identify Class I Aminoacyl-tRNA Synthetase Evolutionary Mosaicity and Inter-Modular Coupling. Int J Mol Sci 2022; 23:ijms23031520. [PMID: 35163448 PMCID: PMC8835825 DOI: 10.3390/ijms23031520] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 01/17/2022] [Accepted: 01/17/2022] [Indexed: 02/01/2023] Open
Abstract
The role of aminoacyl-tRNA synthetases (aaRS) in the emergence and evolution of genetic coding poses challenging questions concerning their provenance. We seek evidence about their ancestry from curated structure-based multiple sequence alignments of a structurally invariant “scaffold” shared by all 10 canonical Class I aaRS. Three uncorrelated phylogenetic metrics—mutation frequency, its uniformity, and row-by-row cladistic congruence—imply that the Class I scaffold is a mosaic assembled from successive genetic sources. Metrics for different modules vary in accordance with their presumed functionality. Sequences derived from the ATP– and amino acid– binding sites exhibit specific two-way coupling to those derived from Connecting Peptide 1, a third module whose metrics suggest later acquisition. The data help validate: (i) experimental fragmentations of the canonical Class I structure into three partitions that retain catalytic activities in proportion to their length; and (ii) evidence that the ancestral Class I aaRS gene also encoded a Class II ancestor in frame on the opposite strand. A 46-residue Class I “protozyme” roots the Class I tree prior to the adaptive radiation of the Rossmann dinucleotide binding fold that refined substrate discrimination. Such rooting implies near simultaneous emergence of genetic coding and the origin of the proteome, resolving a conundrum posed by previous inferences that Class I aaRS evolved after the genetic code had been implemented in an RNA world. Further, pinpointing discontinuous enhancements of aaRS fidelity establishes a timeline for the growth of coding from a binary amino acid alphabet.
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Affiliation(s)
- Charles W. Carter
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7260, USA
- Correspondence: ; Tel.: +1-919-966-3263
| | - Alex Popinga
- Centre for Computational Evolution, University of Auckland, PB 92019, Auckland 1142, New Zealand; (A.P.); (R.B.)
| | - Remco Bouckaert
- Centre for Computational Evolution, University of Auckland, PB 92019, Auckland 1142, New Zealand; (A.P.); (R.B.)
| | - Peter R. Wills
- Department of Physics and Te Ao Marama Centre for Fundamental Inquiry, University of Auckland, PB 92019, Auckland 1142, New Zealand;
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