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Dr. Taekjip Ha

Bloomberg Distinguished Professor, Biophysics and Biophysical Chemistry and Biomedical Engineering
Investigator, Howard Hughes Medical Institute

The Johns Hopkins University

October 19th, 2018 – Fall Seminar

Time and Location: Noon in Meyerhoff Chemistry, Room 120

Host: Dr. Minjoung Kyoung

 

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.