Evolutionary adaptations that enable enzymes to tolerate oxidative stress
| Autor: | Sanjay Kumar Rohaun, James A. Imlay, Ramakrishnan Sethu |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
Free Radicals Iron medicine.disease_cause Biochemistry Article Catalysis Cellular life 03 medical and health sciences 0302 clinical medicine Physiology (medical) medicine chemistry.chemical_classification Chemistry Adaptation Physiological Anoxic waters Oxygen Oxidative Stress 030104 developmental biology Enzyme Molecular oxygen Oxidation-Reduction 030217 neurology & neurosurgery Biochemical mechanism Function (biology) Oxidative stress |
| Zdroj: | Free Radic Biol Med |
| ISSN: | 0891-5849 |
| DOI: | 10.1016/j.freeradbiomed.2019.01.048 |
| Popis: | Biochemical mechanisms emerged and were integrated into the metabolic plan of cellular life long before molecular oxygen accumulated in the biosphere. When oxygen levels finally rose, they threatened specific types of enzymes: those that use organic radicals as catalysts, and those that depend upon iron centers. Nature has found ways to ensure that such enzymes are still used by contemporary organisms. In some cases they are restricted to microbes that reside in anoxic habitats, but in others they manage to function inside oxygen-filled cells. In the latter case, it is frequently true that the ancestral enzyme has been modified to fend off poisoning. In this review we survey a range of protein adaptations that permit radical-based and low-potential iron chemistry to succeed in oxic environments. In many cases, accessory domains shield the vulnerable radical or metal center from oxygen. In others, the structures of iron cofactors evolved to less oxidizable forms, or alternative metals replaced iron altogether. The overarching view is that some classes of biochemical mechanism are intrinsically incompatible with the presence of oxygen. The structural modification of target enzymes is an under-recognized response to this problem. |
| Databáze: | OpenAIRE |
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