Molecular characterisation of meaB, a novel gene affecting nitrogen metabolite repression in Aspergillus nidulans.

Mutations within the meaB gene elicit the inappropriate expression of several activities subject to nitrogen metabolite repression in Aspergillus nidulans and also have some unrelated phenotypic effects. We have cloned meaB and isolated a full length cDNA clone. Northern analysis has shown that meaB expression is not subject to nitrogen metabolite repression. meaB encodes a novel protein of 418 amino acids and contains a significantly high number of S/TPXX motifs, a motif common in transcriptional regulatory proteins. We have sequenced three mutations within meaB, two of which have an identical phenotype to that produced by gene disruption.