title: Two asparagine synthetases in Saccharomyces cerevisiae.
abstract: In Saccharomyces cerevisiae L-asparagine auxotrophy, resulting from a lack of L-asparagine synthesis, needs simultaneous defects in two genes. This unusual situation is shown to result from the occurrence of two L-asparagine synthetases. The meaning of this duplication remains obscure. The properties of the two enzymes are remarkably similar: both have a molecular weight of 150,000 and they exhibit a slight repression and a similar inhibition by asparagine. Neither one is located in mitochondria and both are probably cytosolic. Their identification so far lies only in their behaviour on ion-exchange chromatography and in the encoding genes.
mesh_terms: D001216:Asparagine / Q000494:pharmacology; D001217:Aspartate-Ammonia Ligase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002852:Chromatography, Ion Exchange; D008025:Ligases / Q000378:metabolism*; D008970:Molecular Weight; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000201:enzymology*
chemical_list: D001216:Asparagine; D008025:Ligases; D001217:Aspartate-Ammonia Ligase