Single-molecule direct visualization of DNA repair proteins on chromatin

2014 Fiscal Year Final Research Report

• Project/Area Number: 24570182
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Biophysics
• Research Institution: The Graduate School for the Creation of New Photonics Industries (2013-2014); Kyoto University (2012)
• Principal Investigator: YOKOTA Hiroaki 光産業創成大学院大学, 光産業創成研究科, 准教授 (90415547)
• Co-Investigator(Renkei-kenkyūsha): SUGASAWA Kaoru 神戸大学, 自然科学系先端融合研究環バイオシグナル研究センター, 教授 (70202124) ; IWAI Shigenori 大阪大学, 基礎工学研究科, 教授 (10168544)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: DNA損傷・修復 / タンパク質 / 核酸の構造 / 動態 / 機能

Outline of Final Research Achievements

To elucidate how mammalian (human) DNA repair proteins recognize base lesions, we performed single-molecule direct visualization of the proteins on DNA. We found that XPC-RAD23B protein complex, which is known to be responsible for damage recognition in mammalian nucleotide excision repair, has high affinity for a lesion and performed one-dimensional bidirectional diffusion on undamaged DNA. The diffusion coefficients of the movement indicate that the protein complex does not always perform rotational tracking of the helical pitch of the DNA while moving along DNA and thus diffuses at much higher rates. The obtained results indicate that the protein complex uses these binding modes for efficient search of DNA lesions scattered throughout the genome from a vast excess of normal bases.

Free Research Field

生物物理学