2023-08-16 10:33:35
A universal metabolic strategy can lead to knowledge of the origin of life – UNSPLASH/CC0 PUBLIC DOMAIN
MADRID, 16 Ago. (EUROPA PRESS) –
A new strategy to answer the question of how the first forms of life were studied the earliest evolution of electron transport chains.
Is about a type of metabolic system used by organisms throughout the tree of life, from bacteria to humans, to produce usable forms of chemical energy.
Despite decades of progress, the origin of life remains uncertain. one of the great unsolved problems of science.
“The most basic features of biology, that organisms are made up of cells, that they transmit genetic information through DNA, that they use protein enzymes to direct their metabolism, arose through specific processes in a very early evolutionary history“said Aaron Goldman, associate professor of biology at Oberlin College.
“Understanding how these most basic biological systems first took shape will not only give us a greater understanding of how life works at the most fundamental level, but what life really is in the first place and how we might search for it beyond Earth.” , highlights this researcher, author of a new perspective article on this new strategy published in the journal ‘Proceedings of the National Academy of Sciences’.
The question of how life arose is typically studied through laboratory experiments that simulate Earth’s earliest environments and look for chemical processes that can create the same types of biomolecules and metabolic reactions that we see in organisms today.
This approach is known as “bottom-up,” as it works with materials that would have been present on prebiotic Earth. Although these “prebiotic chemistry” experiments have successfully shown how life could have originated, they cannot tell us how it actually originated.
Meanwhile, other research is using techniques from evolutionary biology to reconstruct what early life might have looked like based on data from life today. It is what is known as a “top-down” approach, which can tell us about the history of life on Earth.
However, top-down research can only go back to genes that are still conserved in living organisms, and therefore cannot go back to the origin of life. Despite their limitations, top-down and bottom-up research pursue the common goal of discovering the origins of life, and ideally their answers should converge on a common set of conditions.
The new paper published by Goldman, Laurie Barge, a Research Scientist in Astrobiology at NASA’s Jet Propulsion Laboratory (JPL), and their colleagues, attempts to bridge this methodological gap.
Thus, the authors argue that the combination of bottom-up laboratory investigations into possible pathways to the origin of life with top-down evolutionary reconstructions of the earliest forms of life may serve to discover how life actually originated on early Earth.
In their article, they describe a phenomenon fundamental to life today that could be studied by combining bottom-up and top-down research: electron transport chains.
Different types of electron transport chains are specialized to each form of life and the energy metabolism they use: for example, our mitochondria contain an electron transport chain linked to our heterotrophic (food-consuming) energy metabolism; while plants have an entirely different electron transport chain linked to photosynthesis (the generation of energy from sunlight).
And in the microbial world, organisms use a wide range of electron transport chains linked to a variety of different energy metabolisms.
But despite these differences, the authors describe evidence from top-down research that this type of metabolic strategy was used by early life forms. and present several models of ancestral electron transport chains that could date back to very early evolutionary history.
They also discuss the current ascending evidence that suggests that, even before the appearance of life as we know it, the minerals and water in Earth’s first oceans they could have facilitated a chemistry similar to that of electron transport chains.
Drawing on these observations, the authors outline future research strategies that synthesize top-down and bottom-up research on the earliest history of electron transport chains in order to better understand ancient energy metabolism and the origin of life in general.
This study is the culmination of five years of previous work by this multi-institutional, interdisciplinary team led by Barge at JPL, which was funded by the NASA-NSF Origins of Life Think Tank to study how metabolic reactions might have arisen in geological settings of the early Earth.
The team’s previous work has investigated, for example, specific mineral-driven electron transport chain reactions (led by JPL research scientist Jessica Weber); how ancient enzymes may have incorporated prebiotic chemistry into their active sites (led by Goldman); and microbial metabolism in extremely limited-energy environments (led by Doug LaRowe, JPL’s Origins of Life Think Tank.
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