Physiology and genetics of carbamoylphosphate synthesis in Escherichia coli K12
- Cite this article as:
- Mergeay, M., Gigot, D., Beckmann, J. et al. Molec. gen. Genet. (1974) 133: 299. doi:10.1007/BF00332706
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76 mutants have been isolated in which the function of the single carbamoylphosphate synthetase of Escherichia coli K 12 is affected. A wide variety of phenotypes have been observed among these mutants, the most typical ones being: requirement for arginine and uracil, arginineless behaviour, sensitivity towards arginine and sensitivity towards uracil. The mutations have been localized by reciprocal transduction and deletion mapping; all are clustered in the same locus, car. The study of carbamoylphosphate synthesizing activities of these mutants and the combination of car mutations in various in vivo as well as in vitro complementation tests lead to the conclusion that car contains two genes: carA, covering the left part of the locus and coding for the “glutamine subunit” of the enzyme; carB, to the right, governing the synthesis of the heavy subunit of the enzyme.