L-asparaginase-deficient mutants of yeast

Yeast L-asparaginase is a multimeric enzyme for which only a single structural gene has been found. Fourteen mutants deficient in L-asparaginase have been isolated, and they have been located at one site on the genetic map of Saccharomyces cerevisiae. The L-asparaginase gene (aspl) is located about 18 centimorgans from a gene governing tryptophan synthesis (trp4) on fragment 2 of the map.