Periodic Reporting for period 1 - EcolMetabOrigin (The Energetics and Habitat of Metabolic Origin)
Periodo di rendicontazione: 2021-11-01 al 2023-04-30
What is at the focus of this project?
The goals of the project are to obtain a better understanding of the transition from simple chemical reactions on the barren early Earth to the habitats and lifestyles of the first microbial communities that colonized our planet in its youngest days. To investigate this phase of early evolution, Chapter 1 of life's history, we will look at the imprint of early evolution that is preserved in the chemical reactions of life itself — metabolism. On the bottom line, life is a chemical reaction. The life process of simple microbes entails about 1,000 individual reactions that are driven forward in the direction of cell growth. This forward progression of growth is the result of a basic principle of life: Cells couple the uptake and biosynthesis of the compounds they need for growth to chemical reactions that release energy. In humans that reaction is the breakdown of fats, proteins and amino acids using O2 (molecular oxygen) from the atmosphere. At the origin of life there was not O2, but there was abundant hydrogen, H2, which serves as a source of energy for primitive microbes to this day. From its very beginning, the Earth has always made H2 by itself in energy releasing reactions at deep sea hydrothermal vents. If we start our investigation into early evolution from H2 as an energy source and carbon dioxide, CO2, as a source of carbon, a previously unrecognized natural tendency for the reactions of life to unfold becomes evident. This principle allows us to look at the early evolutionary process in terms of energy end energy release.
In our first project section, our initial investigations into the issue have shown that the metabolic reactions of primitive life forms are thermodynamically most favorable under the conditions of H2 producing hydrothermal vents. This gives us clues, based upon evidence preserved in metabolism itself, about the environment in which life arose, clues that we will pursue further. In a second project section, we will be looking for evidence of the transition from purely geochemical reactions to biochemical reactions that are catalyzed by proteins made by cells — enzymes. For this we will be studying the ability of minerals to substitute for enzymes in the central reactions of metabolism under early Earth conditions simulated in the laboratory. In a third project section we will be looking at the diversification of early metabolic types from simple reactions that synthesize acetate or methane, into more complex energy harnessing reactions that involve respiratory chains — the ancient precursors of our own breath of life.
Why is this project important for society?
Why is early evolution important for society? It is part of our human nature to want to know where we come from and how everything began. Every human culture has a narrative for where we come from and how the early environment influences the origin of the world, plants, animals, and humans. By probing the contours of early evolution, we are providing taxpayers with information about the nature of early life on early Earth. This is something that human societies generally view as important information.
What are the objectives?
The objectives, outlined above, are to investigate the nature of energy release in early metabolism, to probe the ability of minerals to serve as evolutionary precursors to enzymes and to reconstruct the early diversification of energy harnessing reactions en route to the first respiratory chains.
The goals of the project are to obtain a better understanding of the transition from simple chemical reactions on the barren early Earth to the habitats and lifestyles of the first microbial communities that colonized our planet in its youngest days. To investigate this phase of early evolution, Chapter 1 of life's history, we will look at the imprint of early evolution that is preserved in the chemical reactions of life itself — metabolism. On the bottom line, life is a chemical reaction. The life process of simple microbes entails about 1,000 individual reactions that are driven forward in the direction of cell growth. This forward progression of growth is the result of a basic principle of life: Cells couple the uptake and biosynthesis of the compounds they need for growth to chemical reactions that release energy. In humans that reaction is the breakdown of fats, proteins and amino acids using O2 (molecular oxygen) from the atmosphere. At the origin of life there was not O2, but there was abundant hydrogen, H2, which serves as a source of energy for primitive microbes to this day. From its very beginning, the Earth has always made H2 by itself in energy releasing reactions at deep sea hydrothermal vents. If we start our investigation into early evolution from H2 as an energy source and carbon dioxide, CO2, as a source of carbon, a previously unrecognized natural tendency for the reactions of life to unfold becomes evident. This principle allows us to look at the early evolutionary process in terms of energy end energy release.
In our first project section, our initial investigations into the issue have shown that the metabolic reactions of primitive life forms are thermodynamically most favorable under the conditions of H2 producing hydrothermal vents. This gives us clues, based upon evidence preserved in metabolism itself, about the environment in which life arose, clues that we will pursue further. In a second project section, we will be looking for evidence of the transition from purely geochemical reactions to biochemical reactions that are catalyzed by proteins made by cells — enzymes. For this we will be studying the ability of minerals to substitute for enzymes in the central reactions of metabolism under early Earth conditions simulated in the laboratory. In a third project section we will be looking at the diversification of early metabolic types from simple reactions that synthesize acetate or methane, into more complex energy harnessing reactions that involve respiratory chains — the ancient precursors of our own breath of life.
Why is this project important for society?
Why is early evolution important for society? It is part of our human nature to want to know where we come from and how everything began. Every human culture has a narrative for where we come from and how the early environment influences the origin of the world, plants, animals, and humans. By probing the contours of early evolution, we are providing taxpayers with information about the nature of early life on early Earth. This is something that human societies generally view as important information.
What are the objectives?
The objectives, outlined above, are to investigate the nature of energy release in early metabolism, to probe the ability of minerals to serve as evolutionary precursors to enzymes and to reconstruct the early diversification of energy harnessing reactions en route to the first respiratory chains.
Our findings to date in this project have uncovered interesting and new insights into the environment within which the reactions of life arose [1], and into the very interesting question of why life does not run backwards, even when the energy needed to make it run forwards is scarce [2]. We are also learning a great deal about the ability of minerals to substitute for enzymes in chemical reactions [3]. In total, 10 publications have emerged from work in this project so far.
1 Wimmer JLE, Xavier JC, Vieira AdN, Pereira DPH, Leidner J, Sousa FL, Kleinermanns K, Preiner M, Martin WF (2021). Energy at origins: Favorable thermodynamics of biosynthetic reactions in the last universal common ancestor (LUCA). Front Microbiol 12:793664.
2 Wimmer JLE, Kleinermanns K, Martin WF (2021). Pyrophosphate and irreversibility in evolution, or why PPi is not an energy currency and why nature chose triphosphates. Front Microbiol 12:759359.
3 Henriques Pereira DP, Leethaus J, Beyazay T, do Nascimento Vieira A, Kleinermanns K, Tüysüz H, Martin WF, Preiner M (2022). Role of geochemical protoenzymes (geozymes) in primordial metabolism: Specific abiotic hydride transfer by metals to the biological redox cofactor NAD+. FEBS J 289:3148–3162.
1 Wimmer JLE, Xavier JC, Vieira AdN, Pereira DPH, Leidner J, Sousa FL, Kleinermanns K, Preiner M, Martin WF (2021). Energy at origins: Favorable thermodynamics of biosynthetic reactions in the last universal common ancestor (LUCA). Front Microbiol 12:793664.
2 Wimmer JLE, Kleinermanns K, Martin WF (2021). Pyrophosphate and irreversibility in evolution, or why PPi is not an energy currency and why nature chose triphosphates. Front Microbiol 12:759359.
3 Henriques Pereira DP, Leethaus J, Beyazay T, do Nascimento Vieira A, Kleinermanns K, Tüysüz H, Martin WF, Preiner M (2022). Role of geochemical protoenzymes (geozymes) in primordial metabolism: Specific abiotic hydride transfer by metals to the biological redox cofactor NAD+. FEBS J 289:3148–3162.
We hope to move the state of the art by harnessing new kinds of previously untapped information to study the process of early evolution. This strategy is working so far.