Dr. Taekjip Ha has developed a bio-engineered, hyper-functional "super" helicase that is capable of unwinding 5000+ base pairs without stopping. The super helicase is designed such that the helicase cannot dissociate until the end of the DNA is encountered, making the processivity of the super helicase theoretically infinite in ideal conditions. Furthermore, it can exert forces in the range of 50-80pN which are currently the strongest helicase forces reported. This super helicase could provide a better alternative to helicases currently used in nanopore sequencing and isothermal PCR.
Benefits over existing helicases: Natural Rep protein is a very poor helicase which can unwind DNA sequences as short as 18 base pairs (bp), and at very high concentrations, only up to 30-50 bp
• Rep-X exhibits extremely enhanced DNA unwinding activity: it can unwind 5000+ bp without stopping
• Rep-X is designed in a way that the helicase cannot physically dissociate until the end of the DNA is encountered.
• Rep-X is an extremely strong protein, which cannot be stopped by forces up to 80 pN which is above the shearing force of double stranded DNA.
By carefully controlling crosslinker length, and specific mutations sites that the crosslinkers target, other helicases can be stabilized in the specific conformation that gives rise to the super-active form (i.e. "Helicase-X").