par Pierard, André 
;Glansdorff, Nicolas ;Mergeay, Maximilien ;Wiame, Jean-Marie
Référence Journal of Molecular Biology, 14, 1, page (23-36)
Publication Publié, 1965
;Glansdorff, Nicolas ;Mergeay, Maximilien ;Wiame, Jean-Marie Référence Journal of Molecular Biology, 14, 1, page (23-36)
Publication Publié, 1965
Article révisé par les pairs
| Résumé : | Eight one-step mutations leading to a double auxotrophy for arginine and the pyrimidines map in a small region of the Escherichia coli chromosome. Mutants bearing these mutations lack glutamino-carbamoyl phosphate synthetase. A mutation leading to sensitivity towards uracil is located within the locus responsible for the double auxotrophy. The joint evidences from genetic and enzymo-logical studies show that these mutations affect a single glutamino-carbamoyl phosphate synthetase which supplies carbamoyl phosphate for both the arginine and pyrimidine pathways. This enzyme is submitted to a double end-product control: (a) cumulative repression of its synthesis by arginine and uracil; (b) partial feedback inhibition of its activity by uridine-5′-monophosphate. The uracil-sensitive mutant has a hyper-retro-inhibited glutamino-carbamoyl phosphate synthetase. © 1965, Academic Press Inc. (London) Ltd.. All rights reserved. |
