Taekjip Ha

For More Information

• Taekjip Ha's Personal Website
• Single Molecule Nanometry Group (Ha Group)

Education

• Ph.D., Physics, Univ. of California, Berkeley, 1996

Biography

Professor Taekjip Ha received his Ph.D. in Physics in 1996, from the University of California, Berkeley. Prior to joining the Physics faculty at the University of Illinois in August 2000, he was a postdoctoral fellow at Lawrence Berkeley National Laboratory (1997) and a postdoctoral research associate in Steven Chu's laboratory in the Department of Physics at Stanford University (1998-2000). He was named 2001 Searle scholar. In 2005, Dr. Ha was named an investigator of the Howard Hughes Medical Institute. In 2008, Dr. Ha was selected by the National Science Foundation to receive a grant to establish and co-direct the Center for the Physics of Living Cells at the University of Illinois.

Professor Ha has achieved many "firsts" in experimental biological physics--the first dectection of dipole-dipole interaction (fluorescence resonance energy transfer, or FRET) between two single molecules; the first observation of "quantum jumps" of single molecules at room temperature; the first detection of the rotation of single molecules; and the first detection of enzyme conformational changes via single-molecule FRET. His most recent work, using single-molecule measurements to understand protein-DNA interactions and enzyme dynamics, has led him to develop novel optical techniques, fluid-handling systems, and surface preparations.

Academic Positions

• Co-director, Center for the Physics of Living Cells, University of Illinois, 09/2008-present
• Professor, University of Illinois at Urbana-Champaign, Department of Physics, 08/2007-present
• Investigator, Howard Hughes Medical Institute, 09/2005-present
• Faculty, University of Illinos at Urbana-Champaign, Institute for Genomic Biology, 01/2005-present

Research Statement

My interest is in using physical concepts and experimental techniques to study fundamental questions in molecular biology. The biological systems under study include helicases that unzip DNA, DNA recombination intermediate called Holliday junction and its associated enzymes, folding and catalysis of hairpin and VS ribozymes, DNA replication machinery, and chromatin remodeling complexes. Our main experimental tool is single-molecule fluorescence spectroscopy and microscopy, supported by nano-mechanical tools such as magnetic and optical tweezers.

Undergraduate Research Opportunities

My lab reaches out to undergraduate students and over the years I have tutored over 12 undergraduate students who have gone on to apply for graduate schools, either at Illinois or other universities. Currently, there are several physics undergraduate students who are working on projects in my lab, including engineering a helicase mutant that reverses its natural direction of movement, and two computer science undergraduate students who are writing codes for super-resolution imaging. One of the missions of the Center for the Physics of Living Cells is to tutor the next generation of scientists in the physics of living cells, thus we have an active group of undergraduate students working on various aspects of this important vision.

Books Edited or Co-Edited (Original Editions)

• Selvin, P.R. and T. Ha, editors, Single Molecule Techniques: A Laboratory Manual, Cold Spring Harbor Laboratory Press, 507 pp., ISBN 978-087969775-4 (2008).

Selected Articles in Journals

• S. Myong, I. Rasnik, C. Joo, T. M. Lohman, and T. Ha. Repetitive shuttling of a motor protein on DNA. Nature 437, 1321-1325 (2005).
• I. Rasnik, S. A. McKinney and T. Ha, Non-blinking and long-lasting single molecule fluorescence imaging. Nature Methods 3, 891-893 (2006).
• S. Myong, M. M. Bruno, A. M. Pyle and T. Ha, Spring-loaded mechanism of DNA unwinding by Hepatitis C Virus NS3 helicase, Science 317, 513-516 (2007).
• S. Hohng, R. Zhou, M. K. Nahas, J. Yu, K. Schulten, D. M. J. Lilley and T. Ha, Fluorescence-force spectroscopy maps two-dimensional reaction landscape of the Holliday junction, Science 318, 279-283 (2007).
• S. Myong, S. Cui, P. V. Cornish, A. Kirchhofer, M. U. Gack, J. U. Jung, K. P. Hopfner and T. Ha, Cytosolic viral sensor RIG-I is a 5'-triphosphate-dependent translocase on double-stranded RNA, Science 323(5917):1070-1074 (2009).
• R. Roy, A. G. Kozlov, T. M. Lohman and T. Ha, SSB protein diffusion on single-stranded DNA stimulates RecA filament formation, Nature 461(7267), 1092-1097 (2009).
• M. Pandey, M., S. Syed, I. Donmez, G. Patel, T. Ha and S. S. Patel, Coordinating DNA replication by means of priming loop and differential synthesis rate, Nature 462, 940-943 (2009).
• C. Grashoff, B. D. Hoffman, M. D. Brenner, R. Zhou, M. Parsons, M. T. Yang, M. A. McLean, S. G. Sligar, C. S. Chen, T. Ha and M. A. Schwartz, "Measuring Mechanical Tension Across Vinculin Reveals Regulation of Focal Adhesion Dynamics", Nature 466, 263-266 (2010).
• A. Jain, R. Liu, B. Ramani, E. Arauz, Y. Ishitsuka, K. Ragunathan, J. Park, J. Chen, Y. K. Xiang and T. Ha, "Probing cellular protein complexes using single-molecule pull-down", Nature 473, 484-488 (2011).
• R. Zhou, A. G. Kozlov, R. Roy, J. Zhang, S. Korolev, T. M. Lohman and T. Ha, "SSB functions as a sliding platform that migrates on DNA via reptation", Cell 146, 222-232 (2011).
• I. Cisse, H. Kim and T. Ha, "A rule of seven in Watson-Crick base pairing of mismatched sequences," Nature Structural & Molecular Biology 19, 623-627 (2012).
• G. Lee, M. Bratkowski, F. Ding, A. Ke and T. Ha, "Elastic coupling between RNA degradation and unwinding by an exoribonuclease," Science, 336, 1726-1729 (2012).
• R. Vafabakhsh and T. Ha, "Extreme bendability of DNA less than 100 base pairs long revealed by single molecule cyclization," Science, 337, 1097-1101 (2012).