1
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Tower J. Selectively advantageous instability in biotic and pre-biotic systems and implications for evolution and aging. FRONTIERS IN AGING 2024; 5:1376060. [PMID: 38818026 PMCID: PMC11137231 DOI: 10.3389/fragi.2024.1376060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 04/15/2024] [Indexed: 06/01/2024]
Abstract
Rules of biology typically involve conservation of resources. For example, common patterns such as hexagons and logarithmic spirals require minimal materials, and scaling laws involve conservation of energy. Here a relationship with the opposite theme is discussed, which is the selectively advantageous instability (SAI) of one or more components of a replicating system, such as the cell. By increasing the complexity of the system, SAI can have benefits in addition to the generation of energy or the mobilization of building blocks. SAI involves a potential cost to the replicating system for the materials and/or energy required to create the unstable component, and in some cases, the energy required for its active degradation. SAI is well-studied in cells. Short-lived transcription and signaling factors enable a rapid response to a changing environment, and turnover is critical for replacement of damaged macromolecules. The minimal gene set for a viable cell includes proteases and a nuclease, suggesting SAI is essential for life. SAI promotes genetic diversity in several ways. Toxin/antitoxin systems promote maintenance of genes, and SAI of mitochondria facilitates uniparental transmission. By creating two distinct states, subject to different selective pressures, SAI can maintain genetic diversity. SAI of components of synthetic replicators favors replicator cycling, promoting emergence of replicators with increased complexity. Both classical and recent computer modeling of replicators reveals SAI. SAI may be involved at additional levels of biological organization. In summary, SAI promotes replicator genetic diversity and reproductive fitness, and may promote aging through loss of resources and maintenance of deleterious alleles.
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Affiliation(s)
- John Tower
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, United States
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2
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Wozniak K, Brzezinski K. Biological Catalysis and Information Storage Have Relied on N-Glycosyl Derivatives of β-D-Ribofuranose since the Origins of Life. Biomolecules 2023; 13:biom13050782. [PMID: 37238652 DOI: 10.3390/biom13050782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/24/2023] [Accepted: 04/29/2023] [Indexed: 05/28/2023] Open
Abstract
Most naturally occurring nucleotides and nucleosides are N-glycosyl derivatives of β-d-ribose. These N-ribosides are involved in most metabolic processes that occur in cells. They are essential components of nucleic acids, forming the basis for genetic information storage and flow. Moreover, these compounds are involved in numerous catalytic processes, including chemical energy production and storage, in which they serve as cofactors or coribozymes. From a chemical point of view, the overall structure of nucleotides and nucleosides is very similar and simple. However, their unique chemical and structural features render these compounds versatile building blocks that are crucial for life processes in all known organisms. Notably, the universal function of these compounds in encoding genetic information and cellular catalysis strongly suggests their essential role in the origins of life. In this review, we summarize major issues related to the role of N-ribosides in biological systems, especially in the context of the origin of life and its further evolution, through the RNA-based World(s), toward the life we observe today. We also discuss possible reasons why life has arisen from derivatives of β-d-ribofuranose instead of compounds based on other sugar moieties.
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Affiliation(s)
- Katarzyna Wozniak
- Department of Structural Biology of Prokaryotic Organisms, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-074 Poznan, Poland
| | - Krzysztof Brzezinski
- Department of Structural Biology of Prokaryotic Organisms, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-074 Poznan, Poland
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3
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Kumar Bandela A, Sadihov‐Hanoch H, Cohen‐Luria R, Gordon C, Blake A, Poppitz G, Lynn DG, Ashkenasy G. The Systems Chemistry of Nucleic‐acid‐Peptide Networks. Isr J Chem 2022. [DOI: 10.1002/ijch.202200030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Anil Kumar Bandela
- Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva 84105 Israel
| | - Hava Sadihov‐Hanoch
- Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva 84105 Israel
| | - Rivka Cohen‐Luria
- Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva 84105 Israel
| | - Christella Gordon
- Chemistry and Biology Emory University 1521 Dickey Drive NE Atlanta GA 30322 USA
| | - Alexis Blake
- Chemistry and Biology Emory University 1521 Dickey Drive NE Atlanta GA 30322 USA
| | - George Poppitz
- Chemistry and Biology Emory University 1521 Dickey Drive NE Atlanta GA 30322 USA
| | - David G. Lynn
- Chemistry and Biology Emory University 1521 Dickey Drive NE Atlanta GA 30322 USA
| | - Gonen Ashkenasy
- Department of Chemistry Ben-Gurion University of the Negev Beer-Sheva 84105 Israel
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4
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Jayaraman V, Toledo‐Patiño S, Noda‐García L, Laurino P. Mechanisms of protein evolution. Protein Sci 2022; 31:e4362. [PMID: 35762715 PMCID: PMC9214755 DOI: 10.1002/pro.4362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/11/2022] [Accepted: 05/14/2022] [Indexed: 11/06/2022]
Abstract
How do proteins evolve? How do changes in sequence mediate changes in protein structure, and in turn in function? This question has multiple angles, ranging from biochemistry and biophysics to evolutionary biology. This review provides a brief integrated view of some key mechanistic aspects of protein evolution. First, we explain how protein evolution is primarily driven by randomly acquired genetic mutations and selection for function, and how these mutations can even give rise to completely new folds. Then, we also comment on how phenotypic protein variability, including promiscuity, transcriptional and translational errors, may also accelerate this process, possibly via "plasticity-first" mechanisms. Finally, we highlight open questions in the field of protein evolution, with respect to the emergence of more sophisticated protein systems such as protein complexes, pathways, and the emergence of pre-LUCA enzymes.
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Affiliation(s)
- Vijay Jayaraman
- Department of Molecular Cell BiologyWeizmann Institute of ScienceRehovotIsrael
| | - Saacnicteh Toledo‐Patiño
- Protein Engineering and Evolution UnitOkinawa Institute of Science and Technology Graduate UniversityOkinawaJapan
| | - Lianet Noda‐García
- Department of Plant Pathology and Microbiology, Institute of Environmental Sciences, Robert H. Smith Faculty of Agriculture, Food and EnvironmentHebrew University of JerusalemRehovotIsrael
| | - Paola Laurino
- Protein Engineering and Evolution UnitOkinawa Institute of Science and Technology Graduate UniversityOkinawaJapan
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5
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Giraud T, Hoschtettler P, Pickaert G, Averlant-Petit MC, Stefan L. Emerging low-molecular weight nucleopeptide-based hydrogels: state of the art, applications, challenges and perspectives. NANOSCALE 2022; 14:4908-4921. [PMID: 35319034 DOI: 10.1039/d1nr06131c] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Over the last twenty years, low-molecular weight gelators and, in particular, peptide-based hydrogels, have drawn great attention from scientists thanks to both their inherent advantages in terms of properties and their high modularity (e.g., number and nature of the amino acids). These supramolecular hydrogels originate from specific peptide self-assembly processes that can be driven, modulated and optimized via specific chemical modifications brought to the peptide sequence. Among them, the incorporation of nucleobases, another class of biomolecules well-known for their abilities to self-assemble, has recently appeared as a new promising and burgeoning approach to finely design supramolecular hydrogels. In this minireview, we would like to highlight the interest, high potential, applications and perspectives of these innovative and emerging low-molecular weight nucleopeptide-based hydrogels.
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Affiliation(s)
- Tristan Giraud
- Université de Lorraine, CNRS, LCPM, F-54000 Nancy, France.
| | | | | | | | - Loic Stefan
- Université de Lorraine, CNRS, LCPM, F-54000 Nancy, France.
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6
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Seebacher F, Beaman J. Evolution of plasticity: metabolic compensation for fluctuating energy demands at the origin of life. J Exp Biol 2022; 225:274636. [PMID: 35254445 DOI: 10.1242/jeb.243214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Phenotypic plasticity of physiological functions enables rapid responses to changing environments and may thereby increase the resilience of organisms to environmental change. Here, we argue that the principal hallmarks of life itself, self-replication and maintenance, are contingent on the plasticity of metabolic processes ('metabolic plasticity'). It is likely that the Last Universal Common Ancestor (LUCA), 4 billion years ago, already possessed energy-sensing molecules that could adjust energy (ATP) production to meet demand. The earliest manifestation of metabolic plasticity, switching cells from growth and storage (anabolism) to breakdown and ATP production (catabolism), coincides with the advent of Darwinian evolution. Darwinian evolution depends on reliable translation of information from information-carrying molecules, and on cell genealogy where information is accurately passed between cell generations. Both of these processes create fluctuating energy demands that necessitate metabolic plasticity to facilitate replication of genetic material and (proto)cell division. We propose that LUCA possessed rudimentary forms of these capabilities. Since LUCA, metabolic networks have increased in complexity. Generalist founder enzymes formed the basis of many derived networks, and complexity arose partly by recruiting novel pathways from the untapped pool of reactions that are present in cells but do not have current physiological functions (the so-called 'underground metabolism'). Complexity may thereby be specific to environmental contexts and phylogenetic lineages. We suggest that a Boolean network analysis could be useful to model the transition of metabolic networks over evolutionary time. Network analyses can be effective in modelling phenotypic plasticity in metabolic functions for different phylogenetic groups because they incorporate actual biochemical regulators that can be updated as new empirical insights are gained.
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Affiliation(s)
- Frank Seebacher
- School of Life and Environmental Sciences, A08, University of Sydney, Sydney, NSW 2006, Australia
| | - Julian Beaman
- College of Science and Engineering, Flinders University, Bedford Park, SA 5042, Australia
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7
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Genome Evolution from Random Ligation of RNAs of Autocatalytic Sets. Int J Mol Sci 2021; 22:ijms222413526. [PMID: 34948321 PMCID: PMC8707343 DOI: 10.3390/ijms222413526] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/08/2021] [Accepted: 12/15/2021] [Indexed: 11/16/2022] Open
Abstract
The evolutionary origin of the genome remains elusive. Here, I hypothesize that its first iteration, the protogenome, was a multi-ribozyme RNA. It evolved, likely within liposomes (the protocells) forming in dry-wet cycling environments, through the random fusion of ribozymes by a ligase and was amplified by a polymerase. The protogenome thereby linked, in one molecule, the information required to seed the protometabolism (a combination of RNA-based autocatalytic sets) in newly forming protocells. If this combination of autocatalytic sets was evolutionarily advantageous, the protogenome would have amplified in a population of multiplying protocells. It likely was a quasispecies with redundant information, e.g., multiple copies of one ribozyme. As such, new functionalities could evolve, including a genetic code. Once one or more components of the protometabolism were templated by the protogenome (e.g., when a ribozyme was replaced by a protein enzyme), and/or addiction modules evolved, the protometabolism became dependent on the protogenome. Along with increasing fidelity of the RNA polymerase, the protogenome could grow, e.g., by incorporating additional ribozyme domains. Finally, the protogenome could have evolved into a DNA genome with increased stability and storage capacity. I will provide suggestions for experiments to test some aspects of this hypothesis, such as evaluating the ability of ribozyme RNA polymerases to generate random ligation products and testing the catalytic activity of linked ribozyme domains.
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8
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Coca JR, Eraña H, Castilla J. Biosemiotics comprehension of PrP code and prion disease. Biosystems 2021; 210:104542. [PMID: 34517077 DOI: 10.1016/j.biosystems.2021.104542] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 09/01/2021] [Accepted: 09/07/2021] [Indexed: 01/01/2023]
Abstract
Prions or PrPSc (prion protein, Scrapie isoform) are proteins with an aberrant three-dimensional conformation that present the ability to alter the three-dimensional structure of natively folded PrPC (prion protein, cellular isoform) inducing its abnormal folding, giving raise to neurological diseases known as Transmissible spongiforms encephalopathies (TSEs) or prion diseases. In this work, through a biosemiotic study, we will analyze the molecular code of meanings that are known in the molecular pathway of PrPC and how it is altered in prion diseases. This biosemiotic code presents a socio-semiotic correlate in organisms that could be unraveled with the ultimate goal of understanding the code of signs that mediates the process. Finally, we will study recent works that indicate possible relationships in the code between prion proteins and other proteins such as the tau protein and alpha-synuclein to evaluate if it is possible that there is a semiotic expansion of the PrP code and prion diseases in the meaning recently expounded by Prusiner, winner of the Nobel Prize for describing these unusual pathological processes.
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Affiliation(s)
- Juan R Coca
- Social Research Unit in Health and Rare Diseases, University of Valladolid, Spain.
| | - Hasier Eraña
- Center for Cooperative Research in Biosciences (CIC BioGUNE), Basque Research and Technology Alliance (BRTA), Derio, Spain; Atlas Molecular Pharma S. L., Derio, Spain
| | - Joaquín Castilla
- Center for Cooperative Research in Biosciences (CIC BioGUNE), Basque Research and Technology Alliance (BRTA), Derio, Spain; IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
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9
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Bizzarri BM, Fanelli A, Botta L, De Angelis M, Palamara AT, Nencioni L, Saladino R. Aminomalononitrile inspired prebiotic chemistry as a novel multicomponent tool for the synthesis of imidazole and purine derivatives with anti-influenza A virus activity. RSC Adv 2021; 11:30020-30029. [PMID: 35480240 PMCID: PMC9040849 DOI: 10.1039/d1ra05240c] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 08/30/2021] [Indexed: 12/21/2022] Open
Abstract
Amino imidazole carbonitrile derivatives decorated with α-amino acid side-chains have been synthesized by a multicomponent microwave assisted reaction inspired by the prebiotic chemistry of aminomalononitrile as a tool for generating high chemical diversity. These compounds were used as annulation synthons for the preparation of 8,9-disubstituted-6,9-dihydro-1H-purin-6-ones by reaction with formic acid as a simple C-1 donor reagent. The novel heterocycles were characterized by significant activity against influenza A virus, amino imidazole carbonitrile derivatives showing the highest activity. Thus, the chemical complexity generated by prebiotic chemistry furnished a general tool for the identification of novel antiviral agents. Amino imidazole carbonitrile derivatives decorated with α-amino acid side-chains have been synthesized by a multicomponent microwave assisted reaction inspired by the prebiotic chemistry of aminomalononitrile for generating high chemical diversity.![]()
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Affiliation(s)
- Bruno Mattia Bizzarri
- Ecological and Biological Sciences Department (DEB), University of Tuscia Via S. Camillo de Lellis snc 01100 Viterbo Italy
| | - Angelica Fanelli
- Ecological and Biological Sciences Department (DEB), University of Tuscia Via S. Camillo de Lellis snc 01100 Viterbo Italy
| | - Lorenzo Botta
- Ecological and Biological Sciences Department (DEB), University of Tuscia Via S. Camillo de Lellis snc 01100 Viterbo Italy
| | - Marta De Angelis
- Department of Public Health and Infectious Diseases, Laboratory Affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome Piazzale Aldo Moro, 5 00185 Rome Italy
| | - Anna Teresa Palamara
- Department of Public Health and Infectious Diseases, Laboratory Affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome Piazzale Aldo Moro, 5 00185 Rome Italy .,Department of Infectious Diseases, Istituto Superiore di Sanità Viale Regina Elena, 299 00161 Rome Italy
| | - Lucia Nencioni
- Department of Public Health and Infectious Diseases, Laboratory Affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome Piazzale Aldo Moro, 5 00185 Rome Italy
| | - Raffaele Saladino
- Ecological and Biological Sciences Department (DEB), University of Tuscia Via S. Camillo de Lellis snc 01100 Viterbo Italy
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10
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Davila AF. Life on Mars: Independent Genesis or Common Ancestor? ASTROBIOLOGY 2021; 21:802-812. [PMID: 33848439 DOI: 10.1089/ast.2020.2397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The possibility of biological transfer between planetary bodies is seldom factored into life detection strategies, although the actuality of such an event would have profound implications for how we interpret potential biosignatures found on other worlds. This article addresses the possibility of life on Mars in the context of a biological transfer and an independent genesis of life. The phylogenetic tree of life on Earth is used as a blueprint to interpret evidence of life and as a guideline to determine the likelihood that potential biosignatures could be expressed by martian organisms. Several transfer scenarios are considered, depending on the timing of transfer with respect to the evolution of life on Earth. The implications of each transfer scenario and an independent genesis of life on the biochemical nature of the resulting martian organisms are discussed. The analysis highlights how conceding the possibility of a biological transfer has practical implications for how we search for evidence of life, both in terms of the quality of potential biosignatures and the likelihood that certain biosignatures might be expressed. It is concluded that a degree of uncertainty on the origin of martian organisms might be unavoidable, particularly in the absence of a biochemical context.
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Affiliation(s)
- Alfonso F Davila
- NASA Ames Research Center, Exobiology Branch, Moffett Field, California, USA
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11
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Wang W, Qiao L, He J, Ju Y, Yu K, Kan G, Guo C, Zhang H, Jiang J. Water Microdroplets Allow Spontaneously Abiotic Production of Peptides. J Phys Chem Lett 2021; 12:5774-5780. [PMID: 34134488 DOI: 10.1021/acs.jpclett.1c01083] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The chemistry of abiotic synthesis of peptides in the context of their prebiotic origins is a continuing challenge that arises from thermodynamic and kinetic constraints in aqueous media. Here we reported a strategy of microdroplets' mass spectrometry for peptide bonds formed from pure amino acids or a mixture in the presence of phosphoric acids in aqueous microdroplets. In contrast to bulk experiments, the condensation reactions proceed spontaneously under ambient conditions. The microdroplet gave a negative free-energy change (ΔG ∼ -1.1 kcal/mol), and product yields of ∼75% were obtained at the scale of a few milliseconds. Experiments in which nebulization gas pressure and external charge were varied established dependence of peptide production on the droplet size that has a high surface-to-volume ratio. It is concluded that the condensation reactions occurred at or near the air-water interfaces of microdroplets. This aqueous microdroplets approach also provides a route for chemistry synthesis in the prebiotic era.
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Affiliation(s)
- Wenxin Wang
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong 264209, China
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang 150090, China
| | - Lina Qiao
- Marine College, Shandong University (Weihai), Weihai, Shandong 264209, China
| | - Jing He
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong 264209, China
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang 150090, China
| | - Yun Ju
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong 264209, China
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang 150090, China
| | - Kai Yu
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong 264209, China
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang 150090, China
| | - Guangfeng Kan
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong 264209, China
| | - Changlu Guo
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong 264209, China
| | - Hong Zhang
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong 264209, China
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang 150090, China
| | - Jie Jiang
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, Shandong 264209, China
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, Heilongjiang 150090, China
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12
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Can coacervation unify disparate hypotheses in the origin of cellular life? Curr Opin Colloid Interface Sci 2021. [DOI: 10.1016/j.cocis.2020.101415] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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13
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Xu D, Wang Y. Protein-free ribosomal RNA scaffolds can assemble poly-lysine oligos from charged tRNA fragments. Biochem Biophys Res Commun 2021; 544:81-85. [PMID: 33545497 PMCID: PMC7936610 DOI: 10.1016/j.bbrc.2021.01.036] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 01/13/2021] [Indexed: 01/28/2023]
Abstract
Ribosomal protein synthesis is a central process of the modern biological world. Because the ribosome contains proteins itself, it is very important to understand its precursor and evolution. Small ribozymes have demonstrated the principle of "RNA world" hypothesis, but protein free peptide ligase remains elusive. In this report, we have identified two fragments in the peptidyl transfer center that can synthesize a 9-mer poly-lysine in a solution contains Mg2+. This result is deduced from isotope-shifting in high resolution MS. To our best knowledge, this is the longest peptide oligo that can be synthesized by a pure ribozyme. Via single molecule FRET experiments, we have demonstrated the ligase mechanism was probably by substrate proximity via dimerization. We prospect that these RNA fragments can be useful to synthesize template free natural and non-natural peptides, to be model system for peptidyl transfer reaction mechanism and can shed light to the evolution of ribosome.
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Affiliation(s)
- Doris Xu
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, USA.
| | - Yuhong Wang
- Department of Biology and Biochemistry, University of Houston, Houston, TX, 77204, USA.
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14
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Qu T, Calabrese P, Singhavi P, Tower J. Incorporating antagonistic pleiotropy into models for molecular replicators. Biosystems 2020; 201:104333. [PMID: 33359635 DOI: 10.1016/j.biosystems.2020.104333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 12/17/2020] [Accepted: 12/17/2020] [Indexed: 11/15/2022]
Abstract
In modern cells, chromosomal genes composed of DNA encode multi-subunit protein/RNA complexes that catalyze the replication of the chromosome and cell. One prevailing theory for the origin of life posits an early stage involving self-replicating macromolecules called replicators, which can be considered genes capable of self-replication. One prevailing theory for the genetics of aging in humans and other organisms is antagonistic pleiotropy, which posits that a gene can be beneficial in one context, and detrimental in another context. We previously reported that the conceptual simplicity of molecular replicators facilitates the generation of two simple models involving antagonistic pleiotropy. Here a third model is proposed, and each of the three models is presented with improved definition of the time variable. Computer simulations were used to calculate the proliferation of a hypothetical two-subunit replicator (AB), when one of the two subunits (B) exhibits antagonistic pleiotropy, leading to an advantage for B to be unstable. In model 1, instability of B yields free A subunits, which in turn stimulate the activity of other AB replicators. In model 2, B is lost and sometimes replaced by a more active mutant form, B'. In model 3, B becomes damaged and loses activity, and its instability allows it to be replaced by a new B. For each model, conditions were identified where instability of B was detrimental, and where instability of B was beneficial. The results are consistent with the hypothesis that antagonistic pleiotropy can promote molecular instability and system complexity, and provide further support for a model linking aging and evolution.
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Affiliation(s)
- Tianjiao Qu
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA
| | - Peter Calabrese
- Quantitative and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA
| | - Pratik Singhavi
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA
| | - John Tower
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA.
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15
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Liquid Crystal Peptide/DNA Coacervates in the Context of Prebiotic Molecular Evolution. CRYSTALS 2020. [DOI: 10.3390/cryst10110964] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Liquid–liquid phase separation (LLPS) phenomena are ubiquitous in biological systems, as various cellular LLPS structures control important biological processes. Due to their ease of in vitro assembly into membraneless compartments and their presence within modern cells, LLPS systems have been postulated to be one potential form that the first cells on Earth took on. Recently, liquid crystal (LC)-coacervate droplets assembled from aqueous solutions of short double-stranded DNA (s-dsDNA) and poly-L-lysine (PLL) have been reported. Such LC-coacervates conjugate the advantages of an associative LLPS with the relevant long-range ordering and fluidity properties typical of LC, which reflect and propagate the physico-chemical properties of their molecular constituents. Here, we investigate the structure, assembly, and function of DNA LC-coacervates in the context of prebiotic molecular evolution and the emergence of functional protocells on early Earth. We observe through polarization microscopy that LC-coacervate systems can be dynamically assembled and disassembled based on prebiotically available environmental factors including temperature, salinity, and dehydration/rehydration cycles. Based on these observations, we discuss how LC-coacervates can in principle provide selective pressures effecting and sustaining chemical evolution within partially ordered compartments. Finally, we speculate about the potential for LC-coacervates to perform various biologically relevant properties, such as segregation and concentration of biomolecules, catalysis, and scaffolding, potentially providing additional structural complexity, such as linearization of nucleic acids and peptides within the LC ordered matrix, that could have promoted more efficient polymerization. While there are still a number of remaining open questions regarding coacervates, as protocell models, including how modern biologies acquired such membraneless organelles, further elucidation of the structure and function of different LLPS systems in the context of origins of life and prebiotic chemistry could provide new insights for understanding new pathways of molecular evolution possibly leading to the emergence of the first cells on Earth.
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