The present invention provides for a synthetic transcription factor (TF) comprising a first peptide capable of binding a target ligand, a second peptide capable of binding a target DNA, and a peptide linker linking the first and second peptides. The present invention also provide for a system for modulating the mutagenesis frequency of a host cell. The host cell has a mutator rate (R) which is inversely proportional to a phenotypic trait (P).
STATEMENT OF GOVERNMENTAL SUPPORT
 The invention described and claimed herein was made utilizing funds supplied by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. The government has certain rights in this invention.