Nucleotide substitution: C?T.
The C15 enhancer has been mutated in the 'M5' and M7 Mad binding clusters. Some of the nucleotides in the M7 region have been substituted for others, while some nucleotides have been deleted.
Nucleotide substitution: C?A.
Nucleotide substitution: G?T.
Nucleotide substitution: G?A.