Descrizione del progetto
Un approccio fisiologico e chimico alla scoperta delle prime forme di vita sulla Terra
L’origine della vita sulla Terra rimane un grande mistero. La vita è una reazione chimica, ma come, dove e da cosa ha avuto origine? Come è avvenuta la diversificazione primordiale del metabolismo? Il progetto EcolMetabOrigin, finanziato dal CER, cerca di trovare una risposta a questi interrogativi attraverso la chimica metabolica e le probabili reazioni biochimiche. I partner del progetto si avvarranno di strumenti di fisiologia comparativa, termodinamica e genomica comparativa in uno studio all’avanguardia sul processo di esordio dell’evoluzione metabolica. In particolare, EcolMetabOrigin studierà le proprietà termodinamiche delle attuali reti metaboliche, in cerca di informazioni conservate dall’origine geochimica del metabolismo microbico, e la relativa traiettoria evolutiva fino all’origine e alla diffusione di eme e citocromi nel corso della diversificazione microbica iniziale.
Obiettivo
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.
Campo scientifico
Programma(i)
Argomento(i)
Meccanismo di finanziamento
ERC-ADG - Advanced GrantIstituzione ospitante
40225 Dusseldorf
Germania