Base de dados : MEDLINE
Pesquisa : G16.650 [Categoria DeCS]
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  1 / 2124 MEDLINE  
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[PMID]:29339755
[Au] Autor:Rout SK; Friedmann MP; Riek R; Greenwald J
[Ad] Endereço:Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093, Zürich, Switzerland.
[Ti] Título:A prebiotic template-directed peptide synthesis based on amyloids.
[So] Source:Nat Commun;9(1):234, 2018 01 16.
[Is] ISSN:2041-1723
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The prebiotic replication of information-coding molecules is a central problem concerning life's origins. Here, we report that amyloids composed of short peptides can direct the sequence-selective, regioselective and stereoselective condensation of amino acids. The addition of activated DL-arginine and DL-phenylalanine to the peptide RFRFR-NH in the presence of the complementary template peptide Ac-FEFEFEFE-NH yields the isotactic product FRFRFRFR-NH , 1 of 64 possible triple addition products, under conditions in which the absence of template yields only single and double additions of mixed stereochemistry. The templating mechanism appears to be general in that a different amyloid formed by (Orn)V(Orn)V(Orn)V(Orn)V-NH and Ac-VDVDVDVDV-NH is regioselective and stereoselective for N-terminal, L-amino-acid addition while the ornithine-valine peptide alone yields predominantly sidechain condensation products with little stereoselectivity. Furthermore, the templating reaction is stable over a wide range of pH (5.6-8.6), salt concentration (0-4 M NaCl), and temperature (25-90 °C), making the amyloid an attractive model for a prebiotic peptide replicating system.
[Mh] Termos MeSH primário: Aminoácidos/química
Amiloide/química
Técnicas de Química Sintética/métodos
Peptídeos/química
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Aminoácidos/genética
Aminoácidos/metabolismo
Amiloide/metabolismo
Amiloide/ultraestrutura
Arginina/química
Arginina/genética
Arginina/metabolismo
Concentração de Íons de Hidrogênio
Microscopia Eletrônica
Origem da Vida
Biossíntese Peptídica/genética
Peptídeos/genética
Peptídeos/metabolismo
Fenilalanina/química
Fenilalanina/genética
Fenilalanina/metabolismo
Cloreto de Sódio/química
Estereoisomerismo
Temperatura Ambiente
Moldes Genéticos
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Amino Acids); 0 (Amyloid); 0 (Peptides); 451W47IQ8X (Sodium Chloride); 47E5O17Y3R (Phenylalanine); 94ZLA3W45F (Arginine)
[Em] Mês de entrada:1803
[Cu] Atualização por classe:180305
[Lr] Data última revisão:
180305
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180118
[St] Status:MEDLINE
[do] DOI:10.1038/s41467-017-02742-3


  2 / 2124 MEDLINE  
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[PMID]:29323115
[Au] Autor:Becker S; Schneider C; Okamura H; Crisp A; Amatov T; Dejmek M; Carell T
[Ad] Endereço:Center for Integrated Protein Science Munich CiPSM at the Department of Chemistry, Ludwig-Maximilians-Universität München, 81377, Munich, Germany.
[Ti] Título:Wet-dry cycles enable the parallel origin of canonical and non-canonical nucleosides by continuous synthesis.
[So] Source:Nat Commun;9(1):163, 2018 01 11.
[Is] ISSN:2041-1723
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The molecules of life were created by a continuous physicochemical process on an early Earth. In this hadean environment, chemical transformations were driven by fluctuations of the naturally given physical parameters established for example by wet-dry cycles. These conditions might have allowed for the formation of (self)-replicating RNA as the fundamental biopolymer during chemical evolution. The question of how a complex multistep chemical synthesis of RNA building blocks was possible in such an environment remains unanswered. Here we report that geothermal fields could provide the right setup for establishing wet-dry cycles that allow for the synthesis of RNA nucleosides by continuous synthesis. Our model provides both the canonical and many ubiquitous non-canonical purine nucleosides in parallel by simple changes of physical parameters such as temperature, pH and concentration. The data show that modified nucleosides were potentially formed as competitor molecules. They could in this sense be considered as molecular fossils.
[Mh] Termos MeSH primário: Biopolímeros/química
Nucleosídeos/química
RNA/química
Água/química
[Mh] Termos MeSH secundário: Terra (Planeta)
Evolução Química
Modelos Químicos
Estrutura Molecular
Origem da Vida
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Biopolymers); 0 (Nucleosides); 059QF0KO0R (Water); 63231-63-0 (RNA)
[Em] Mês de entrada:1803
[Cu] Atualização por classe:180305
[Lr] Data última revisão:
180305
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180112
[St] Status:MEDLINE
[do] DOI:10.1038/s41467-017-02639-1


  3 / 2124 MEDLINE  
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[PMID]:28470848
[Au] Autor:Camprubi E; Jordan SF; Vasiliadou R; Lane N
[Ad] Endereço:Department of Genetics, Evolution and Environment, University College London, London, UK.
[Ti] Título:Iron catalysis at the origin of life.
[So] Source:IUBMB Life;69(6):373-381, 2017 06.
[Is] ISSN:1521-6551
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Iron-sulphur proteins are ancient and drive fundamental processes in cells, notably electron transfer and CO fixation. Iron-sulphur minerals with equivalent structures could have played a key role in the origin of life. However, the 'iron-sulphur world' hypothesis has had a mixed reception, with questions raised especially about the feasibility of a pyrites-pulled reverse Krebs cycle. Phylogenetics suggests that the earliest cells drove carbon and energy metabolism via the acetyl CoA pathway, which is also replete in Fe(Ni)S proteins. Deep differences between bacteria and archaea in this pathway obscure the ancestral state. These differences make sense if early cells depended on natural proton gradients in alkaline hydrothermal vents. If so, the acetyl CoA pathway diverged with the origins of active ion pumping, and ancestral CO fixation might have been equivalent to methanogens, which depend on a membrane-bound NiFe hydrogenase, energy converting hydrogenase. This uses the proton-motive force to reduce ferredoxin, thence CO . The mechanism suggests that pH could modulate reduction potential at the active site of the enzyme, facilitating the difficult reduction of CO by H . This mechanism could be generalised under abiotic conditions so that steep pH differences across semi-conducting Fe(Ni)S barriers drives not just the first steps of CO fixation to C1 and C2 organics such as CO, CH SH and CH COSH, but a series of similar carbonylation and hydrogenation reactions to form longer chain carboxylic acids such as pyruvate, oxaloacetate and α-ketoglutarate, as in the incomplete reverse Krebs cycle found in methanogens. We suggest that the closure of a complete reverse Krebs cycle, by regenerating acetyl CoA directly, displaced the acetyl CoA pathway from many modern groups. A later reliance on acetyl CoA and ATP eliminated the need for the proton-motive force to drive most steps of the reverse Krebs cycle. © 2017 IUBMB Life, 69(6):373-381, 2017.
[Mh] Termos MeSH primário: Acetilcoenzima A/química
Ferredoxinas/química
Proteínas com Ferro-Enxofre/química
Ferro/química
Origem da Vida
[Mh] Termos MeSH secundário: Acetilcoenzima A/metabolismo
Archaea/química
Archaea/metabolismo
Bactérias/química
Bactérias/metabolismo
Ciclo do Carbono
Dióxido de Carbono/química
Dióxido de Carbono/metabolismo
Catálise
Ciclo do Ácido Cítrico
Ferredoxinas/metabolismo
Concentração de Íons de Hidrogênio
Fontes Hidrotermais
Ferro/metabolismo
Proteínas com Ferro-Enxofre/metabolismo
Ácidos Cetoglutáricos/química
Ácidos Cetoglutáricos/metabolismo
Ácido Oxaloacético/química
Ácido Oxaloacético/metabolismo
Prótons
Ácido Pirúvico/química
Ácido Pirúvico/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Ferredoxins); 0 (Iron-Sulfur Proteins); 0 (Ketoglutaric Acids); 0 (Protons); 142M471B3J (Carbon Dioxide); 2F399MM81J (Oxaloacetic Acid); 72-89-9 (Acetyl Coenzyme A); 8558G7RUTR (Pyruvic Acid); 8ID597Z82X (alpha-ketoglutaric acid); E1UOL152H7 (Iron)
[Em] Mês de entrada:1803
[Cu] Atualização por classe:180305
[Lr] Data última revisão:
180305
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170505
[St] Status:MEDLINE
[do] DOI:10.1002/iub.1632


  4 / 2124 MEDLINE  
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[PMID]:28454764
[Au] Autor:Lupas AN; Alva V
[Ad] Endereço:Department of Protein Evolution, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany. Electronic address: andrei.lupas@tuebingen.mpg.de.
[Ti] Título:Ribosomal proteins as documents of the transition from unstructured (poly)peptides to folded proteins.
[So] Source:J Struct Biol;198(2):74-81, 2017 May.
[Is] ISSN:1095-8657
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:For the most part, contemporary proteins can be traced back to a basic set of a few thousand domain prototypes, many of which were already established in the Last Universal Common Ancestor of life on Earth, around 3.5 billion years ago. The origin of these domain prototypes, however, remains poorly understood. One hypothesis posits that they arose from an ancestral set of peptides, which acted as cofactors of RNA-mediated catalysis and replication. Initially, these peptides were entirely dependent on the RNA scaffold for their structure, but as their complexity increased, they became able to form structures by excluding water through hydrophobic contacts, making them independent of the RNA scaffold. Their ability to fold was thus an emergent property of peptide-RNA coevolution. The ribosome is the main survivor of this primordial RNA world and offers an excellent model system for retracing the steps that led to the folded proteins of today, due to its very slow rate of change. Close to the peptidyl transferase center, which is the oldest part of the ribosome, proteins are extended and largely devoid of secondary structure; further from the center, their secondary structure content increases and supersecondary topologies become common, although the proteins still largely lack a hydrophobic core; at the ribosomal periphery, supersecondary structures coalesce around hydrophobic cores, forming folds that resemble those seen in proteins of the cytosol. Collectively, ribosomal proteins thus offer a window onto the time when proteins were acquiring the ability to fold.
[Mh] Termos MeSH primário: Evolução Molecular
Origem da Vida
Dobramento de Proteína
Proteínas Ribossômicas/química
[Mh] Termos MeSH secundário: Peptídeos/química
Conformação Proteica
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Peptides); 0 (Ribosomal Proteins)
[Em] Mês de entrada:1803
[Cu] Atualização por classe:180305
[Lr] Data última revisão:
180305
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170430
[St] Status:MEDLINE


  5 / 2124 MEDLINE  
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[PMID]:29311556
[Au] Autor:Springsteen G; Yerabolu JR; Nelson J; Rhea CJ; Krishnamurthy R
[Ad] Endereço:Department of Chemistry, Furman University, Greenville, SC, 29613, USA.
[Ti] Título:Linked cycles of oxidative decarboxylation of glyoxylate as protometabolic analogs of the citric acid cycle.
[So] Source:Nat Commun;9(1):91, 2018 01 08.
[Is] ISSN:2041-1723
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The development of metabolic approaches towards understanding the origins of life, which have focused mainly on the citric acid (TCA) cycle, have languished-primarily due to a lack of experimentally demonstrable and sustainable cycle(s) of reactions. We show here the existence of a protometabolic analog of the TCA involving two linked cycles, which convert glyoxylate into CO and produce aspartic acid in the presence of ammonia. The reactions proceed from either pyruvate, oxaloacetate or malonate in the presence of glyoxylate as the carbon source and hydrogen peroxide as the oxidant under neutral aqueous conditions and at mild temperatures. The reaction pathway demonstrates turnover under controlled conditions. These results indicate that simpler versions of metabolic cycles could have emerged under potential prebiotic conditions, laying the foundation for the appearance of more sophisticated metabolic pathways once control by (polymeric) catalysts became available.
[Mh] Termos MeSH primário: Dióxido de Carbono/química
Glioxilatos/química
Modelos Químicos
Origem da Vida
Ácido Oxaloacético/química
Ácido Pirúvico/química
[Mh] Termos MeSH secundário: Amônia/química
Ácido Aspártico/química
Descarboxilação
Peróxido de Hidrogênio/química
Concentração de Íons de Hidrogênio
Cinética
Malonatos/química
Redes e Vias Metabólicas
Oxirredução
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Glyoxylates); 0 (Malonates); 142M471B3J (Carbon Dioxide); 2F399MM81J (Oxaloacetic Acid); 30KYC7MIAI (Aspartic Acid); 7664-41-7 (Ammonia); 8558G7RUTR (Pyruvic Acid); 9KX7ZMG0MK (malonic acid); BBX060AN9V (Hydrogen Peroxide); JQ39C92HH6 (glyoxylic acid)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180222
[Lr] Data última revisão:
180222
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180110
[St] Status:MEDLINE
[do] DOI:10.1038/s41467-017-02591-0


  6 / 2124 MEDLINE  
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[PMID]:28786485
[Au] Autor:Agmon I
[Ad] Endereço:Institute for Advanced Studies in Theoretical Chemistry, Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa, Israel.
[Ti] Título:Sequence complementarity at the ribosomal Peptidyl Transferase Centre implies self-replicating origin.
[So] Source:FEBS Lett;591(20):3252-3258, 2017 Oct.
[Is] ISSN:1873-3468
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:A feasible scenario for the emergence of life requires the spontaneous materialization and sustainability of a proto-ribosome that could have catalysed the formation of the first peptides. Models of proto-ribosomes were derived from the ribosomal Peptidyl Transferase Centre (PTC) region, but the poor prebiotic copying abilities give rise to the question of their mode of replication. Here, complementarity is demonstrated in bacterial ribosomes, between nucleotides that constitute the two halves of the PTC cavity. The complementarity corroborates the dimeric nature of the proto-ribosome and is likely to underlie the symmetry of the PTC region. Furthermore, it indicates a simple and efficient replication mode; the strand of each monomer could have acted as a template for the synthesis of its counterpart, forming a self-replicating ribozyme.
[Mh] Termos MeSH primário: Origem da Vida
Peptidil Transferases/química
RNA Catalítico/química
RNA Ribossômico 23S/química
Ribossomos/metabolismo
[Mh] Termos MeSH secundário: Pareamento de Bases
Biocatálise
Escherichia coli/genética
Escherichia coli/metabolismo
Evolução Molecular
Modelos Biológicos
Modelos Moleculares
Conformação de Ácido Nucleico
Peptidil Transferases/genética
Peptidil Transferases/metabolismo
RNA Catalítico/genética
RNA Catalítico/metabolismo
RNA Ribossômico 23S/genética
RNA Ribossômico 23S/metabolismo
Ribossomos/genética
Ribossomos/ultraestrutura
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (RNA, Catalytic); 0 (RNA, Ribosomal, 23S); EC 2.3.2.12 (Peptidyl Transferases)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171031
[Lr] Data última revisão:
171031
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170809
[St] Status:MEDLINE
[do] DOI:10.1002/1873-3468.12781


  7 / 2124 MEDLINE  
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[PMID]:28723913
[Au] Autor:Kinsler G; Sinai S; Lee NK; Nowak MA
[Ad] Endereço:Dept. Applied Mathematics, School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, United States of America.
[Ti] Título:Prebiotic selection for motifs in a model of template-free elongation of polymers within compartments.
[So] Source:PLoS One;12(7):e0180208, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The transition from prelife where self-replication does not occur, to life which exhibits self-replication and evolution, has been a subject of interest for many decades. Membranes, forming compartments, seem to be a critical component of this transition as they provide several concurrent benefits. They maintain localized interactions, generate electro-chemical gradients, and help in selecting cooperative functions as they arise. These functions pave the way for the emergence and maintenance of simple metabolic cycles and polymers. In the context of origin of life, evolution of information-carrying molecules and RNA based enzymes within compartments has been subject to intensive theoretical and experimental research. Hence, many experimental efforts aim to produce compartments that contain elongating polynucleotides (also referred to as protocells), which store information and perform catalysis. Despite impressive experimental progress, we are still relatively ignorant about the dynamics by which elongating polynucleotides can produce more sophisticated behaviors. Here we perform computer simulations to couple information production through template-free elongation of polymers with dividing compartments. We find that polymers with a simple ability-biasing the concentration of monomers within their own compartment-can acquire a selective advantage in prelife. We further investigate whether such a mechanism allows for cooperative dynamics to dominate over purely competitive ones. We show that under this system of biased monomer addition, even without template-directed self-replication, genetic motifs can emerge, compete, cooperate, and ultimately survive within the population.
[Mh] Termos MeSH primário: Evolução Biológica
Origem da Vida
Polímeros
Prebióticos
[Mh] Termos MeSH secundário: Células Artificiais
Simulação por Computador
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Polymers); 0 (Prebiotics)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170922
[Lr] Data última revisão:
170922
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170721
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0180208


  8 / 2124 MEDLINE  
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[PMID]:28700697
[Au] Autor:Szostak N; Synak J; Borowski M; Wasik S; Blazewicz J
[Ad] Endereço:Institute of Computing Science, Poznan University of Technology, Poznan, Poland.
[Ti] Título:Simulating the origins of life: The dual role of RNA replicases as an obstacle to evolution.
[So] Source:PLoS One;12(7):e0180827, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Despite years of study, it is still not clear how life emerged from inanimate matter and evolved into the complex forms that we observe today. One of the most recognized hypotheses for the origins of life, the RNA World hypothesis, assumes that life was sparked by prebiotic replicating RNA chains. In this paper, we address the problems caused by the interplay between hypothetical prebiotic RNA replicases and RNA parasitic species. We consider the coexistence of parasite RNAs and RNA replicases as well as the impact of parasites on the further evolution of replicases. For these purposes, we used multi-agent modeling techniques that allow for realistic assumptions regarding the movement and spatial interactions of modeled species. The general model used in this study is based on work by Takeuchi and Hogeweg. Our results confirm that the coexistence of parasite RNAs and replicases is possible in a spatially extended system, even if we take into consideration more realistic assumptions than Takeuchi and Hogeweg. However, we also showed that the presence of trade-off that takes into the account an RNA folding process could still pose a serious obstacle to the evolution of replication. We conclude that this might be a cause for one of the greatest transitions in life that took place early in evolution-the separation of the function between DNA templates and protein enzymes, with a central role for RNA species.
[Mh] Termos MeSH primário: RNA Replicase/metabolismo
[Mh] Termos MeSH secundário: Evolução Biológica
Origem da Vida
RNA/genética
RNA Replicase/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
63231-63-0 (RNA); EC 2.7.7.48 (RNA Replicase)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170925
[Lr] Data última revisão:
170925
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170713
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0180827


  9 / 2124 MEDLINE  
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[PMID]:28669113
[Au] Autor:Yarus M
[Ad] Endereço:Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO, 80309-0347, USA. yarus@stripe.colorado.edu.
[Ti] Título:Efficient Heritable Gene Expression Readily Evolves in RNA Pools.
[So] Source:J Mol Evol;84(5-6):236-252, 2017 Jun.
[Is] ISSN:1432-1432
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Heritable gene expression arises readily in a simple non-genetic system employing known small-RNA biochemistry. Pooled cross-templating ribonucleotides show varied chemical competence on which selection acts, even calculating only minimal effects. Evolution can be quick-computed progress toward encoded gene expression can require only days or weeks for two millimolar, partly activated complementary 5' ribonucleotides. After only one product selection cycle, early templating can become prevailing pool behavior. Subsequently, a selected templated product is efficiently amplified as a pool ages, frequently accumulated in the same order of concentration as incoming nucleotides. Pools spontaneously favor templating because sporadic nucleotide accumulations increase it-and selection increases templating in pools of all ages. Nonetheless, templated chemical competence appears most easily in young pools. Pool history is critical-pools can perish from periodic hazards (like tides), or alternatively, from hazards roughly constant in time (like rainfall). Selection is greatly enhanced in constant hazard pools-more effective if pools have varied ages. Stronger selection is disproportionately more effective. Selected evolutionary change has an uncomplicated molecular basis-progress from chemical product synthesis to templated, proto-genetic inheritance exploits identity between templating and entropic catalysis. Though discovered by computation, selection of an elevated product of template catalysis is plausible, independent of any chemical or mathematical assumption. Selected chemical variation before genetics (chance utility) therefore inaugurates inheritance, even when hindered by unstable, dilute nucleotides, erratically supplied in undependable quantities. Remarkably, such uncontrolled conditions are not necessarily hostile, but can instead accelerate appearance of primordial gene-like behavior.
[Mh] Termos MeSH primário: RNA/química
RNA/genética
[Mh] Termos MeSH secundário: Expressão Gênica/genética
Nucleotídeos/genética
Origem da Vida
Ribonucleotídeos/genética
Seleção Genética/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Nucleotides); 0 (Ribonucleotides); 63231-63-0 (RNA)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171026
[Lr] Data última revisão:
171026
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170703
[St] Status:MEDLINE
[do] DOI:10.1007/s00239-017-9800-1


  10 / 2124 MEDLINE  
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[PMID]:28664404
[Au] Autor:Higgs PG
[Ad] Endereço:Origins Institute and Department of Physics and Astronomy, McMaster University, Hamilton, ON, Canada. higgsp@mcmaster.ca.
[Ti] Título:Chemical Evolution and the Evolutionary Definition of Life.
[So] Source:J Mol Evol;84(5-6):225-235, 2017 Jun.
[Is] ISSN:1432-1432
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Darwinian evolution requires a mechanism for generation of diversity in a population, and selective differences between individuals that influence reproduction. In biology, diversity is generated by mutations and selective differences arise because of the encoded functions of the sequences (e.g., ribozymes or proteins). Here, I draw attention to a process that I will call chemical evolution, in which the diversity is generated by random chemical synthesis instead of (or in addition to) mutation, and selection acts on physicochemical properties, such as hydrolysis, photolysis, solubility, or surface binding. Chemical evolution applies to short oligonucleotides that can be generated by random polymerization, as well as by template-directed replication, and which may be too short to encode a specific function. Chemical evolution is an important stage on the pathway to life, between the stage of "just chemistry" and the stage of full biological evolution. A mathematical model is presented here that illustrates the differences between these three stages. Chemical evolution leads to much larger differences in molecular concentrations than can be achieved by selection without replication. However, chemical evolution is not open-ended, unlike biological evolution. The ability to undergo Darwinian evolution is often considered to be a defining feature of life. Here, I argue that chemical evolution, although Darwinian, does not quite constitute life, and that a good place to put the conceptual boundary between non-life and life is between chemical and biological evolution.
[Mh] Termos MeSH primário: Evolução Química
Origem da Vida
[Mh] Termos MeSH secundário: Evolução Biológica
Replicação do DNA
Mutação
Oligonucleotídeos/metabolismo
Polimerização
RNA/metabolismo
RNA Catalítico/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Oligonucleotides); 0 (RNA, Catalytic); 63231-63-0 (RNA)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171026
[Lr] Data última revisão:
171026
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170701
[St] Status:MEDLINE
[do] DOI:10.1007/s00239-017-9799-3



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