What is ade1 and ADE2?
Mutations in two of these genes are especially useful, because, in addition to requiring adenine, their colonies develop a pink or red color. These were the first two adenine-requiring mutants discovered, so they are called ade1 and ade2.
What is ADE2 gene?
The ADE2 gene encodes AIR-carboxylase which catalyzes the sixth step of the purine biosynthetic pathway in Saccharomyces cerevisiae. We have analyzed the effect of deletions in the promoter region of this gene on the expression of the enzyme using a fusion of the ADE2 gene promoter to the bacterial lacZ gene.
What enzyme does ADE2 encode?
phosphoribosylaminoimidazole carboxylase
The ADE2 gene encodes phosphoribosylaminoimidazole carboxylase, a bifunctional enzyme that catalyzes the sixth step of de novo purine biosynthesis.
How much adenine is in yeast?
VanDusen et al. () reported on high variability of adenine content among yeast extracts of different vendors and different batches (ranging from 0.34 up to 1.91 mg g−1 yeast extract). The YPD media used in experiments described here contained 13 mg L−1 of adenine.
Why are ADE2 mutants red?
The red pigment in ade1 and ade2 strains results from oxidative metabolism of the intermediate, called AIR, in the AMP synthesis pathway. If AIR is not produced or if it is not acted on by oxidative metabolism the red pigment does not form.
On which chromosome is ADE2 located?
chromosome V
ADE1 was localized at chromosome III, closely linked to the mating type gene, making it a convenient marker for mating type. ADE2 was localized at chromosome V.
How many amino acids is the ADE2 protein?
568 amino acid residues
The nucleotide sequence of the Candida albicans ADE2 gene, which encodes phosphoribosylaminoimidazole carboxylase, has been determined. The sequence possesses an uninterrupted open reading frame of 1704 nucleotides corresponding to 568 amino acid residues.
Why is some yeast red?
It is only when the adenine in the medium is used up and the yeast attempt to synthesize their own, that they begin to accumulate the red pigment due to the block in adenine biosyntheis. Streak out the yeast on YED. It should start to look pink after a couple of days’ growth on YED.