Project description
A physiological and chemical approach to finding the first life forms on Earth
The origin of life on Earth remains a great mystery. Life is a chemical reaction. But how, where and from what did the chemical reaction of life arise? How did the primordial diversification of metabolism proceed? The ERC-funded EcolMetabOrigin project seeks to answer these questions through metabolic chemistry and likely biochemical reactions. Project partners will apply the tools of comparative physiology, thermodynamics and comparative genomics in a pioneering investigation of the process of early metabolic evolution. Specifically, EcolMetabOrigin will investigate thermodynamic properties of modern metabolic networks in search of information retained from the geochemical origin of microbial metabolism, its evolutionary trajectory up to the origin and spread of heme and cytochromes during early microbial diversification.
Objective
Life is a chemical reaction. Over 1000 individual reactions are driven in the direction of cell growth by the coupling of biosyntheses to environmentally available exergonic reactions that are harnessed by a handful of enzymes in energy metabolism. How, where, and from what the chemical reaction of life arose, and how the primordial diversification of metabolism proceeded are the topics of this proposal. Evidence for the process of metabolic origin and traces from the very early course of microbial evolution should be preserved in the chemical reactions of metabolism itself. This concept, traditionally germane to thoughts on biochemical evolution, is (almost) self evident: Enzymes do not perform feats of magic, they just accelerate reactions that tend to occur anyway. Biochemical reactions can therefore themselves harbor relics of, or be holdovers from, metabolic origin. Yet not all reactions are equally old, metabolism has evolved — but how? In this proposal, the tools of comparative physiology, thermodynamics, and comparative genomics, will be applied to investigate the process of early metabolic evolution. Three kinds of data stand central to the work: i) thermodynamic properties of reactions that comprise modern metabolic networks, ii) information contained in the ability of H2 in the presence of Ni3Fe and magnetite catalysts to substitute for ferredoxin and enzymes in biochemical reactions, and iii) information about the evolutionary origin and phylogenetic spread of heme and cytochromes as well as the ecophysiological context of cytochrome origin. The proposed work will deliver groundbreaking insights into the chemical environment at the site of biochemical origins, inform about the pre-enzymatic nature of catalysts and reductants at the origin of metabolism, and offer insights into the course of bioenergetic evolution before and after heme as well as the ancestral function of cytochromes in accessing extracellular electron acceptors.
Fields of science
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Funding Scheme
ERC-ADG - Advanced GrantHost institution
40225 Dusseldorf
Germany