The carboxy-terminal domain of ROS1 is essential for 5-methylcytosine DNA glycosylase activity.

ABSTRACT: Arabidopsis thaliana repressor of silencing 1 (ROS1) is a multi-domain bifunctional DNA glycosylase/lyase, which excises 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) as well as thymine and 5-hydroxymethyluracil (i.e., the deamination products of 5mC and 5hmC) when paired with a guanine, leaving an apyrimidinic (AP) site that is subsequently incised by the lyase activity. ROS1 is slow in base excision and fast in AP lyase activity, indicating that the recognition of pyrimidine modifications might be a rate-limiting step. In the C-terminal half, the enzyme harbors a helix-hairpin-helix DNA glycosylase domain followed by a unique C-terminal domain. We show that the isolated glycosylase domain is inactive for base excision but retains partial AP lyase activity. Addition of the C-t

SUBMITTER: Hong S 

PROVIDER: S-EPMC4253907 | biostudies-literature | 2014 Nov

REPOSITORIES: biostudies-literature