The Escherichia coli methyl - directed reaction has been reconstituted in a purified system
consisting of MutH, MutL, and MutS
proteins, DNA helicase II,
single - strand DNA binding
protein, DNA polymerase III holoenzyme, exonuclease I, DNA ligase, along with ATP (adenosine triphosphate), and the four deoxynucleoside triphosphates.