Metabolic channelling of carbamoyl phosphate in the hyperthermophilic archaeon Pyrococcus furiosus: dynamic enzyme-enzyme interactions involved in the formation of the channelling complex
Massant, J.; Glansdorff, N. (2004). Metabolic channelling of carbamoyl phosphate in the hyperthermophilic archaeon Pyrococcus furiosus: dynamic enzyme-enzyme interactions involved in the formation of the channelling complex. Biochem. Soc. Trans. 32(2): 306-309. dx.doi.org/10.1042/BST0320306
In: Biochemical Society Transactions. Portland Press: London. ISSN 0300-5127; e-ISSN 1470-8752, meer
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| Author keywords |
carbamoyl phosphate metabolism; enzyme-enzyme interactions;hyperthermophile; metabolic channelling; molecular physiology;thermostability |
| Auteurs | | Top |
- Massant, J.
- Glansdorff, N., meer
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| Abstract |
Protection of thermolabile metabolites and coenzymes is a somewhat neglected but essential aspect of the molecular physiology of hyperthermophiles. Detailed information about the mechanisms used by thermophiles to protect these thermolabile metabolites and coenzymes is still scarce. A case in point is CP (carbamoyl phosphate), a precursor of pyrimidines and arginine, which is an extremely labile and potentially toxic intermediate. Recently we obtained the first evidence for a physical interaction between two hyperthermophilic enzymes for which kinetic evidence had suggested that these enzymes channel a highly thermolabile and potentially toxic intermediate. By physically interacting with each other, CKase (carbamate kinase) and OTCase (ornithine carbarnoyltransferase) prevent thermodenaturation of CP in the aqueous cytoplasmic environment. The CP channelling complex involving CKase and OTCase or ATCase (aspartate carbarnoyltransferase), identified in hyperthermophilic archaea, provides a good model system to investigate the mechanism of metabolic channelling and the molecular basis of pfotein-protein interactions in the physiology of extreme thermophiles. |
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