title: Incorporation of amino acid analogs during the biosynthesis of Escherichia coli aspartate transcarbamylase.
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.
mesh_terms: D000409:Alanine / Q000031:analogs & derivatives / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism*; D001221:Aspartate Carbamoyltransferase / Q000096:biosynthesis*; D004926:Escherichia coli / Q000201:enzymology*; D005001:Ethionine / Q000378:metabolism; D046911:Macromolecular Substances; D008762:Methylhistidines / Q000378:metabolism; D010649:Phenylalanine / Q000031:analogs & derivatives / Q000378:metabolism; D014230:Triazoles / Q000378:metabolism; D014364:Tryptophan / Q000031:analogs & derivatives / Q000378:metabolism; D010135:p-Fluorophenylalanine / Q000378:metabolism
chemical_list: D000596:Amino Acids; D046911:Macromolecular Substances; D008762:Methylhistidines; D014230:Triazoles; C003633:triazolealanine; C006657:7-azatryptophan; C027217:2-fluorophenylalanine; C027218:3-fluorophenylalanine; D010649:Phenylalanine; D010135:p-Fluorophenylalanine; D014364:Tryptophan; D001221:Aspartate Carbamoyltransferase; D000409:Alanine; D005001:Ethionine