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A prebiotic basis for ATP as the universal energy currency
- Source :
- PLoS biology. 20(10)
- Publication Year :
- 2021
-
Abstract
- ATP is universally conserved as the principal energy currency in cells, driving metabolism through phosphorylation and condensation reactions. Such deep conservation suggests that ATP arose at an early stage of biochemical evolution. Yet purine synthesis requires 6 phosphorylation steps linked to ATP hydrolysis. This autocatalytic requirement for ATP to synthesize ATP implies the need for an earlier prebiotic ATP equivalent, which could drive protometabolism before purine synthesis. Why this early phosphorylating agent was replaced, and specifically with ATP rather than other nucleoside triphosphates, remains a mystery. Here, we show that the deep conservation of ATP might reflect its prebiotic chemistry in relation to another universally conserved intermediate, acetyl phosphate (AcP), which bridges between thioester and phosphate metabolism by linking acetyl CoA to the substrate-level phosphorylation of ADP. We confirm earlier results showing that AcP can phosphorylate ADP to ATP at nearly 20% yield in water in the presence of Fe3+ ions. We then show that Fe3+ and AcP are surprisingly favoured. A wide range of prebiotically relevant ions and minerals failed to catalyse ADP phosphorylation. From a panel of prebiotic phosphorylating agents, only AcP, and to a lesser extent carbamoyl phosphate, showed any significant phosphorylating potential. Critically, AcP did not phosphorylate any other nucleoside diphosphate. We use these data, reaction kinetics, and molecular dynamic simulations to infer a possible mechanism. Our findings might suggest that the reason ATP is universally conserved across life is that its formation is chemically favoured in aqueous solution under mild prebiotic conditions.
- Subjects :
- Adenosine Diphosphate
Diphosphates
Kinetics
Adenosine Triphosphate
Carbamyl Phosphate
General Immunology and Microbiology
Acetyl Coenzyme A
General Neuroscience
Water
Nucleosides
General Agricultural and Biological Sciences
General Biochemistry, Genetics and Molecular Biology
Organophosphates
Subjects
Details
- ISSN :
- 15457885
- Volume :
- 20
- Issue :
- 10
- Database :
- OpenAIRE
- Journal :
- PLoS biology
- Accession number :
- edsair.doi.dedup.....22f2de20885f94750ef7da275ef38cf8