Construct: Nucleotide substitution: G3227C. Nucleotide substitution: C3228T. Nucleotide substitution: C3229G. Nucleotide substitution: G3230C. Nucleotide substitution: C3231A. Nucleotide substitution: C3232G. Nucleotide substitution: G3233T. The Mad binding site 3221bp downstream of the ato transcriptional start site has been mutated.