Saccharomyces cerevisiae produces two L-asparaginases (ASPs), intracellular ASP I and cell-wall ASP II. In this report, the ASP-I-encoding gene, ASP1, has been identified by homology cloning based on the structures of ASPs from other organisms. Its deduced protein product has a subunit M(r) of 41,414, and shows substantial sequence homology to the bacterial amidohydrolase family. The product of the S. cerevisiae ASP3 gene, a further member of this family, encoding the nitrogen catabolite-regulated cell-wall ASP II, has 46% overall sequence identity to ASP1. Duplication of ancestral asparaginase genes, resulting in separate intra- and extracellular isozymes, appears to have occurred independently in the prokaryotic and eukaryotic lineages. Exact physical mapping of the new cloned ASP1 gene locates it 73% of the distance from the left telomere of chromosome IV, at a position precisely matching the known genetic map location of ASP1. This, along with the structural features of the clone, confirms that ASP1 is the structural gene encoding cytoplasmic ASP I in S. cerevisiae. Sequence analysis of the ethylmethanesulfonate-induced asp1-12 allele of strain XE101-1A revealeda C-->T transition altering Ala176 to Val. This residue lies within a highly conserved region, and the results suggests a critical function for Ala176 in ASP function. Expression of ASP1 and other recombinant ASPs may allow access to improved products for use in the chemotherapy of leukaemia.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Reference||Annotation Extension|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Conditions||Strain||Source||Reference|