Event Date: 15 May 2015 08:00 AM - 15 May 2015 09:00 AM

Event Venue: Enterprise Wing, Level 5, Perseverance Rooms 1/2

Diversity of DNA structures under high tension

by Dr Xinghua Zhang

Seminar Abstract
DNA has multiple structures depending on conditions. Previous single-molecule studies revealed that mechanical stretching of force could induce formation of overstretched DNA structures from the most common B-form DNA structure. Three possible structures have been proposed and debated for 17 years, namely:  1) peeled ssDNA, 2) DNA bubble, and 3) S-DNA.  By thermodynamics, mechanical and electrostatic studies, we have successfully identified all the three proposed structures. We also found interconversions between overstretched DNA structures can be induced by changing buffer conditions.
The published papers were highlighted by Biopolymer on Volume 97(8), released twice by NUS Science Press Releases, and reported by dozens of medias. Currently, we are studying the physiological functions of the three overstretched DNA structures, and explore the presence of any new DNA structures under both force and torque.

Speaker’s Biography
Dr. Zhang is currently a Research Scientist in BioSystems and Micromechanics Inter-Disciplinary Research Group of Singapore-MIT Alliance for Research and Technology (SMART). He received his Ph.D. in condensed matter physics, from Institute of Physics, Chinese Academy of Sciences. He was a patent examiner at State Intellectual Property Office of China from 2009 to 2010. His current research interests are diversity of DNA structures, and initiation of biofilm formation.