Molecular Mechanism For Vitamin Cderived C5glycerylmethylcytosine Dna Modification Catalyzed By Algal Tet Homologue Cmd1 Wenjing Li Tianlong Zhang Mingliang Sun Yu Shi Xiaojie Zhang Guoliang Xu Jianping Ding by Wenjing Li & Tianlong Zhang & Mingliang Sun & Yu Shi & Xiao-jie Zhang & Guo-liang Xu & Jianping Ding instant download after payment.

C5-glyceryl-methylcytosine (5gmC) is a novel DNA modification catalyzed by algal TEThomologue CMD1 using vitamin C (VC) as co-substrate. Here, we report the structures ofCMD1 in apo form and in complexes with VC or/and dsDNA. CMD1 exhibits comparablebinding affinities for DNAs of different lengths, structures, and 5mC levels, and displays amoderate substrate preference for 5mCpG-containing DNA. CMD1 adopts the typical DSBHfold of Fe2+/2-OG-dependent dioxygenases. The lactone form of VC binds to the active siteand mono-coordinates the Fe2+ in a manner different from 2-OG. The dsDNA binds to apositively charged cleft of CMD1 and the 5mC/C is inserted into the active site and recognized by CMD1 in a similar manner as the TET proteins. The functions of key residues arevalidated by mutagenesis and activity assay. Our structural and biochemical data togetherreveal the molecular mechanism for the VC-derived 5gmC DNA modification by CMD1.