Methylation-independent DNA binding modulates specificity of Repressor of Silencing 1 (ROS1) and facilitates demethylation in long substrates.

ABSTRACT: DNA cytosine methylation is an epigenetic mark that promotes gene silencing and performs critical roles during reproduction and development in both plants and animals. The genomic distribution of DNA methylation is the dynamic outcome of opposing methylation and demethylation processes. In plants, active demethylation occurs through a base excision repair pathway initiated by 5-methycytosine (5-meC) DNA glycosylases of the REPRESSOR OF SILENCING 1 (ROS1)/DEMETER (DME) family. To gain insight into the mechanism by which Arabidopsis ROS1 recognizes and excises 5-meC, we have identified those protein regions that are required for efficient DNA binding and catalysis. We have found that a short N-terminal lysine-rich domain conserved in members of the ROS1/DME family mediates strong methylation

SUBMITTER: Ponferrada-Marin MI 

PROVIDER: S-EPMC2906296 | biostudies-literature | 2010 Jul

REPOSITORIES: biostudies-literature