Autocatalytic chemical networks preceded proteins and RNA in evolution

2019 ◽  
Author(s):  
Joana C. Xavier ◽  
Wim Hordijk ◽  
Stuart Kauffman ◽  
Mike Steel ◽  
William F. Martin
Keyword(s):  
Amino Acids ◽  
Origin Of Life ◽  
Small Molecule ◽  
Metabolic Networks ◽  
Early Earth ◽  
Prebiotic Evolution ◽  
Biochemical Evolution ◽  
The Origin Of Life ◽  
Acids And Bases ◽  
Open Question

AbstractModern cells embody metabolic networks containing thousands of elements and form autocatalytic molecule sets that produce copies of themselves. How the first self-sustaining metabolic networks arose at life’ s origin is a major open question. Autocatalytic molecule sets smaller than metabolic networks were proposed as transitory intermediates at the origin of life, but evidence for their role in prebiotic evolution is lacking. Here we identify reflexively autocatalytic food-generated networks (RAFs)—self-sustaining networks that collectively catalyze all their reactions—embedded within microbial metabolism. RAFs in the metabolism of ancient anaerobic autotrophs that live from H2 and CO2 generate amino acids and bases, the monomeric components of protein and RNA, and acetyl-CoA, but amino acids and bases do not generate metabolic RAFs, indicating that small-molecule catalysis preceded polymers in biochemical evolution. RAFs uncover intermediate stages in the origin of metabolic networks, narrowing the gaps between early-Earth chemistry and life.

scholarly journals Autocatalytic chemical networks at the origin of metabolism

2020 ◽  
Vol 287 (1922) ◽  
pp. 20192377 ◽  
Author(s):  
Joana C. Xavier ◽  
Wim Hordijk ◽  
Stuart Kauffman ◽  
Mike Steel ◽  
William F. Martin
Keyword(s):  
Amino Acids ◽  
Origin Of Life ◽  
Small Molecule ◽  
Metabolic Networks ◽  
Early Earth ◽  
Prebiotic Evolution ◽  
Autocatalytic Sets ◽  
The Origin Of Life ◽  
Acids And Bases ◽  
Open Question

Modern cells embody metabolic networks containing thousands of elements and form autocatalytic sets of molecules that produce copies of themselves. How the first self-sustaining metabolic networks arose at life's origin is a major open question. Autocatalytic sets smaller than metabolic networks were proposed as transitory intermediates at the origin of life, but evidence for their role in prebiotic evolution is lacking. Here, we identify reflexively autocatalytic food-generated networks (RAFs)—self-sustaining networks that collectively catalyse all their reactions—embedded within microbial metabolism. RAFs in the metabolism of ancient anaerobic autotrophs that live from H 2 and CO 2 provided with small-molecule catalysts generate acetyl-CoA as well as amino acids and bases, the monomeric components of protein and RNA, but amino acids and bases without organic catalysts do not generate metabolic RAFs. This suggests that RAFs identify attributes of biochemical origins conserved in metabolic networks. RAFs are consistent with an autotrophic origin of metabolism and furthermore indicate that autocatalytic chemical networks preceded proteins and RNA in evolution. RAFs uncover intermediate stages in the emergence of metabolic networks, narrowing the gaps between early Earth chemistry and life.

The sulfocyanic theory on the origin of life: towards a critical reappraisal of an autotrophic theory

2003 ◽  
Vol 2 (4) ◽  
pp. 301-306 ◽  
Author(s):  
L. Perezgasga ◽  
E. Silva ◽  
A. Lazcano ◽  
A. Negrón-Mendoza
Keyword(s):  
Amino Acids ◽  
Origin Of Life ◽  
Raw Materials ◽  
Total Yield ◽  
Historical Analysis ◽  
Preliminary Identification ◽  
Chemical Significance ◽  
The Origin Of Life ◽  
Materials Used ◽  
Emergence Of Life

In the early 1930s, Alfonso L. Herrera proposed his so-called sulfocyanic theory on the origin of life, an autotrophic proposal on the first living beings according to which NH4SCN and H2CO acted as raw materials for the synthesis of bio-organic compounds inside primordial photosynthetic protoplasmic structures. Although the work of Herrera is frequently cited in historical analysis of the development of the origin of life studies, very little attention has been given to the chemical significance of the reactions he published. In this paper we report the results of our search for amino acids obtained from a reactive mixture used by Herrera from 1933 onwards. Chromatograms using the high-pressure liquid chromatography (HPLC) technique suggest the presence of several amino acids, the total yield being 2% of the initial thiocyanate used. Preliminary identification based on HPLC retention times suggests the presence of glycine, alanine, cysteine and methionine. Alanine was the most abundant amino acid in all samples of fractionated material analysed. Although the starting materials used by Herrera were determined by his autotrophic hypothesis on the origin of cells, our results show that his experiments may provide insights into the abiotic synthesis of sulfur-containing amino acids within the framework of a heterotrophic emergence of life.

scholarly journals Impact-Induced Hydrothermal Systems on Early Earth: CH4 Production and the Origin of Life

2020 ◽  
Author(s):  
Kazumu Kaneko ◽  
Yasuhito Sekine ◽  
Takazo Shibuya ◽  
Hisahiro Ueda ◽  
Natsumi Noda
Keyword(s):  
Origin Of Life ◽  
Hydrothermal Systems ◽  
Early Earth ◽  
Ch4 Production ◽  
The Origin Of Life

scholarly journals Ariel – a window to the origin of life on early earth?

2020 ◽  
Author(s):  
Martin Ferus ◽  
Vojtěch Adam ◽  
Giuseppe Cassone ◽  
Svatopluk Civiš ◽  
Václav Čuba ◽  
...  
Keyword(s):  
Origin Of Life ◽  
Early Earth ◽  
The Origin Of Life

scholarly journals The Cosmochemical Record of Carbonaceous Meteorites: An Evolutionary Story

2019 ◽  
Vol 53 (4) ◽  
Author(s):  
Sandra Pizzarello
Keyword(s):  
Amino Acids ◽  
Water Soluble ◽  
Early Earth ◽  
The Earth ◽  
Terrestrial Environments ◽  
Extraterrestrial Origin ◽  
Exogenous Delivery ◽  
The Origin Of Life ◽  
The Rich ◽  
Evolutionary Story

This account traces a lecture given to El Colegio Nacional last March during a Conference “On the origin of life on the Earth” organized to celebrate Darwin’s Bicentennial. It reports on the extraterrestrial organic materials found in carbon-containing meteorites, their composition, likely origin and possible prebiotic contribution to early terrestrial environments. Overall, this abiotic chemistry displaysstructures as diverse as kerogen-like macromolecules and simpler soluble compounds, such as amino acids, amines and polyols, and show an isotopic composition that verifies their extraterrestrial origin and lineage to cosmochemical synthetic regimes. Some meteoritic compounds have identical counterpart in the biosphere and encourage the proposal that their exogenous delivery to the early Earth might havefostered molecular evolution. Particularly suggestive in this regard are the unique l-asymmetry of a number of amino acids in some meteorites as well as the rich and almost exclusively water-soluble compositions discovered for other meteorite types.

The origin of life in comets

2007 ◽  
Vol 6 (4) ◽  
pp. 321-323 ◽  
Author(s):  
W.M. Napier ◽  
J.T. Wickramasinghe ◽  
N.C. Wickramasinghe
Keyword(s):  
Origin Of Life ◽  
Aqueous Phase ◽  
Early Earth ◽  
Habitable Zone ◽  
The Galaxy ◽  
Terrestrial Environments ◽  
Prebiotic Environments ◽  
The Origin Of Life

AbstractMechanisms of interstellar panspermia have recently been identified whereby life, wherever it has originated, will disperse throughout the habitable zone of the Galaxy within a few billion years. This re-opens the question of where life originated. The interiors of comets, during their aqueous phase, seem to provide environments no less favourable for the origin of life than that of the early Earth. Their combined mass throughout the Galaxy overwhelms that of suitable terrestrial environments by about 20 powers of ten, while the lifetimes of friendly prebiotic environments within them exceeds that of localized terrestrial regions by another four or five powers of ten. We propose that the totality of comets around G-dwarf Sun-like stars offers an incomparably more probable setting for the origin of life than any that was available on the early Earth.

scholarly journals Experimental fossilisation of viruses from extremophilic Archaea

2011 ◽  
Vol 8 (6) ◽  
pp. 1465-1475 ◽  
Author(s):  
F. Orange ◽  
A. Chabin ◽  
A. Gorlas ◽  
S. Lucas-Staat ◽  
C. Geslin ◽  
...  
Keyword(s):  
Origin Of Life ◽  
Extreme Environments ◽  
Early Earth ◽  
Sulfolobus Islandicus ◽  
Viral Particles ◽  
Rock Record ◽  
Extremophilic Microorganisms ◽  
The Origin Of Life ◽  
Pyrococcus Abyssi

Abstract. The role of viruses at different stages of the origin of life has recently been reconsidered. It appears that viruses may have accompanied the earliest forms of life, allowing the transition from an RNA to a DNA world and possibly being involved in the shaping of tree of life in the three domains that we know presently. In addition, a large variety of viruses has been recently identified in extreme environments, hosted by extremophilic microorganisms, in ecosystems considered as analogues to those of the early Earth. Traces of life on the early Earth were preserved by the precipitation of silica on the organic structures. We present the results of the first experimental fossilisation by silica of viruses from extremophilic Archaea (SIRV2 – Sulfolobus islandicus rod-shaped virus 2, TPV1 – Thermococcus prieurii virus 1, and PAV1 – Pyrococcus abyssi virus 1). Our results confirm that viruses can be fossilised, with silica precipitating on the different viral structures (proteins, envelope) over several months in a manner similar to that of other experimentally and naturally fossilised microorganisms. This study thus suggests that viral remains or traces could be preserved in the rock record although their identification may be challenging due to the small size of the viral particles.

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