Incorporation of amino acid analogs during the biosynthesis of Escherichia coli aspartate transcarbamylase.

P Gueguen, M Padron, B Perbal, G Hervé

Index: Biochim. Biophys. Acta 615(1) , 59-69, (1980)

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Abstract

Amino acid-requiring mutants capable of producing derepressed levels of aspartate transcarbamylase (carbamoylphosphate:L-aspartate carbamoyltransferase, EC 2.1.3.2) were obtained and used for the incorporation in this enzyme of eight different amino acid analogs. These amino acid replacements enabled the biosynthesis of a series of modified aspartate transcarbamylases altered in their catalytic or regulatory properties. The enzyme in which phenylalanine was rereplaced by 2-fluorophenylalanine was purified to homogeneity and appeared to have the same specific activity as normal asparate transcarbamylase but lacking both homotropic and heterotropic interactions.