A full-length Hsp70 promoter is fused upstream of the Ecol\dam open reading frame that has been mutated to contain the amino acid replacement L127C, with the mutation immediately preceeded by the 4-hydroxytamoxifen-inducible intein Tag:4-HT-intein. A Tag:MYC tag has been inserted at the C-terminal end of the Ecol\dam open reading frame. Insertion of the intein sequence partially inactivates the Ecol\dam protein. Intein splicing can be induced by feeding with 4-hydroxytamoxifen.