Structural analysis to investigate the coordinating role of DNA clamp in replisome

2015 Fiscal Year Final Research Report

• Project/Area Number: 24370046
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Structural biochemistry
• Research Institution: Kyushu University
• Principal Investigator: Mayanagi Kouta 九州大学, 生体防御医学研究所, 助教 (50418571)
• Co-Investigator(Kenkyū-buntansha): SHIRAI Tsuyoshi 長浜バイオ大学, 教授 (00262890) ; OYAMA Takuji 山梨大学, 准教授 (60423133)
• Co-Investigator(Renkei-kenkyūsha): ISHINO Yoshizumi 九州大学, (連合)農学研究科, 教授 (30346837)
• Project Period (FY): 2012-04-01 – 2016-03-31
• Keywords: 電子顕微鏡 / ナノバイオ / 生体分子 / 可視化 / 生物物理 / 画像解析 / 複合体 / 立体構造

Outline of Final Research Achievements

PCNA has a trimeric ring structure that encircles the DNA, and increases the processivity of the bound DNA polymerase by tethering it to the DNA. It is known now, that PCNA also interacts with multiple partners, such as DNA ligase and FEN, to control DNA replication, and works not only as the platform, but also as the conductor for the recruitment and release of these factors. However, the molecular architectures as well as the mechanism of the regulation of these replication factors are not known in detail. In order to investigate the switching mechanism between the replication factors in more detail, we studied the complex structures with two replication factors bound to one PCNA ring, by single particle analysis. We could successfully visualize the 3D structure of FEN-DNA ligase-PCNA-DNA complex, the intermediate state of Okazaki fragment maturation, and the handing over of the ds DNA strand from FEN to DNA ligase.

Free Research Field

構造生物学