Monofunctional DNA glycosylase targeting U:G and T:G mispairs (PubMed:23994068). Excises uracil derivatives and exhibits a preference for a CpG sequence context, irrespective of the methylation status of the complementary strand (PubMed:23994068). The activity follows a biphasic kinetics, with an initial burst of product accumulation followed by a slower phase (PubMed:23994068). Specifically binds its reaction product (PubMed:23994068). Triggers the base excision repair (BER) pathway (PubMed:25900572). Isoform 1 and isoform 4: Expressed in leaves and flowers, but not in roots or stems. The N-terminal domain (1-290) does not play any direct role in catalysis and is not required for product binding. This putative homolog of vertebrate MBD4 DNA glycosylase is designated as MBD4L (MBD4-like) to avoid nomenclature confusion with a protein with a conserved MBD but no DNA glycosylase domain already called MBD4 (AC Q9LYB9). Truncated N-terminus.