2018 Fall Physics Colloquium 

강연일자: 2018. 10. 2. 화. 오후 5시

장소: 아산이학관 433호

강연자: 이자일 (UNIST)

강연주제: DNA curtain: a novel single-molecule imaging method

                 to investigate the details underlying biological reactions

Technical advance in biophysics enables us to investigate the veiled details of biological reactions at the molecular level. Recently the advent of single-molecule spectroscopy facilitates inspecting how biomolecules are interacting with others in more detail. To date many single-molecule techniques have been developed and highly applied to numerous cases of biological research. Here we introduce a novel single-molecule imaging technique called DNA curtain, which is a hybrid system combining lipid fluidity, nano-technique and fluorescence microscopy. This technique provides a unique platform to directly visualize individual proteins working on a single DNA molecule in real time. Using the DNA curtain, we studied a DNA translocase FtsK that is rapidly moves on DNA. We characterized the biophysical properties of FtsK and investigated the collision of FtsK with other DNA binding proteins. This study gives us an insight into how proteins cope with the crowded environments of DNA inside cells. Furthermore, we also studied how human NER (nucleotide excision repair) protein, hXPC-Rad23B can search for DNA lesions. It navigates along DNA through one-dimensional diffusion, in particular, hopping mechanism. We found that hXPC-Rad23B has constrained motion at certain points sometimes. These points had high correlation with the consecutive AT tracks.