ジャーナル: Nat Plants / 年: 2023 タイトル: Molecular basis of the plant ROS1-mediated active DNA demethylation. 著者: Xuan Du / Zhenlin Yang / Guohui Xie / Changshi Wang / Laixing Zhang / Kaige Yan / Maojun Yang / Sisi Li / Jian-Kang Zhu / Jiamu Du / 要旨: Active DNA demethylation plays a crucial role in eukaryotic gene imprinting and antagonizing DNA methylation. The plant-specific REPRESSOR OF SILENCING 1/DEMETER (ROS1/DME) family of enzymes directly ...Active DNA demethylation plays a crucial role in eukaryotic gene imprinting and antagonizing DNA methylation. The plant-specific REPRESSOR OF SILENCING 1/DEMETER (ROS1/DME) family of enzymes directly excise 5-methyl-cytosine (5mC), representing an efficient DNA demethylation pathway distinct from that of animals. Here, we report the cryo-electron microscopy structures of an Arabidopsis ROS1 catalytic fragment in complex with substrate DNA, mismatch DNA and reaction intermediate, respectively. The substrate 5mC is flipped-out from the DNA duplex and subsequently recognized by the ROS1 base-binding pocket through hydrophobic and hydrogen-bonding interactions towards the 5-methyl group and Watson-Crick edge respectively, while the different protonation states of the bases determine the substrate preference for 5mC over T:G mismatch. Together with the structure of the reaction intermediate complex, our structural and biochemical studies revealed the molecular basis for substrate specificity, as well as the reaction mechanism underlying 5mC demethylation by the ROS1/DME family of plant-specific DNA demethylases.
分子 #1: Sex-determining region Y protein,DNA glycosylase/AP lyase ROS1
分子
名称: Sex-determining region Y protein,DNA glycosylase/AP lyase ROS1 タイプ: protein_or_peptide / ID: 1 詳細: Fusion protein of residues 56 to 130 of database UNP Q05066, Linker, residues 511 to 1393 of database UNP Q9SJQ6, with deletion of residues 665-835 and 1074-1109. コピー数: 1 / 光学異性体: LEVO / EC番号: DNA-(apurinic or apyrimidinic site) lyase