We tested the efficiency of Chi6 oligodimers (sequence-list) for their potential of inhibiting the exonuclease complex RecBCD in vitro. As a linear DNA Template we used linearized red fluorescent protein (pSB1C3_J04450). The DNA was degraded by commercial RecBCD and evaluated for the DNA concentration left after 0, 5, 10 and 30 minutes.
Linear DNA without Chi6 oligomers is rapidly degraded. When Chi6 oligomers are added, they inhibit RecBCD in a reverse-sigmoidal manner. Within 30 minutes, linear DNA is still degraded, however the general stability of linear DNA fragments in a solution with RecBCD is increased to at least 10 minutes. Because Chi6 is made of linearized DNA itself, it is degraded exponentially.
The activity of Chi6 in vivo should be further evaluated to show the potential as a potent replacement to GamS, an expensive protein-based inhibitor.
iGEM Munich Basic Parts List