Positive regulatory elements involved in urea amidolyase and urea uptake induction in Saccharomyces cerevisiae.

Urea amidolyase and the high affinity urea uptake system are induced by allophanate. durM (-) and durL (-) recessive mutations, which are easily obtained, totally prevent this induction. They are not linked to each other nor to the concerned structural genes. Despite an intensive hunt, no mutation of repressor or classical operator type has been selected. We conclude that urea amidolyase and urea uptake induction involves at least two positive elements coded for by the durM and durL genes.