BIOE Seminar: Taekjip Ha
Friday, September 21, 2018
9:00 a.m.-10:00 a.m.
A. James Clark Hall, Room 2132
Dr. Giuliano Scarcelli
Dr. Taekjip Ha
Bloomberg Distinguished Professor
Biophysics and Biophysical Chemistry
Howard Hughes Medical Institute
Johns Hopkins University
From single molecule fluorescence to superenzyme engineering and beyond
The DNA double helix needs to be unwound into single strands during its replication and repair. ATP-dependent motor proteins called helicases are responsible DNA unwinding. Because untimely generation of single stranded DNA can be toxic to the cell, helicase functions need to be tightly regulated. Using an instrument combining single molecule fluorescence spectroscopy with ultrahigh resolution optical tweezers, we discovered a helicase regulation mechanism via conformational control. Further, we engineered a superhelicase by constraining the enzyme into the unwinding-active conformation. We are currently pursuing several applications of the superenzyme in isothermal DNA amplification, DNA sequencing and co-transcriptional RNA folding and ribonucleic protein assemblies.