Figure 8.

Proposed model for TDG binding to RNA. TDG binds preferentially to G-rich RNA sequences through its structure catalytic domain, resulting in a competition between RNA and DNA for binding to TDG. The CTD prevents nonspecific electrostatic interactions between RNA and the cationic NTD, possibly through direct interactions between the two domains, promoting G-selectivity at the cost of RNA affinity. Upon deletion of the CTD, electrostatic interactions between the NTD and RNA are thus increased, leading to tighter overall binding but reduced selectivity for G. CTD, C-terminal domain; NTD, N-terminal domain; TDG, Thymine DNA glycosylase.