Transcriptional regulator that binds CpG islands in promoters where the DNA is methylated at position 5 of cytosine within CpG dinucleotides. May directly affect chromatin structure by inducing intra- and inter- chromatin compaction via bridging over multiple methylated CpG sites. Acts as an anti-silencing factor that prevents DNA hypermethylation and gene repression (PubMed:25684209). Requires high mCG density for binding (PubMed:25684209, PubMed:25593350). Recognizes preferentially mCGs located in transposable elements (PubMed:25684209, PubMed:25593350). Required for active DNA demethylation (PubMed:25593350). Prefers to target genomic loci around chromocenters (PubMed:25593350). Interacts with PRMT11 (PubMed:17711414). Interacts (via C-terminus) with IDM2, but not with IDM1 (PubMed:25684209, PubMed:25593350). Interacts with IDM3 (PubMed:25684209). Part of a complex made of MBD7, IDM1, IDM2 and IDM3 (PubMed:25684209). Associated with heterochromatin, at all chromocenters. Excluded from nucleolus. Expressed in leaves, buds, flowers, stems, siliques, mature seeds and roots. Highly expressed at the early seedling stage. The methyl-CpG-binding domain (MBD) functions both in binding to methylated DNA and in protein interactions (By similarity). The number of MBD domains may affect binding affinity, mobility within the nucleus, and subnuclear localization (By similarity). The C-terminal domain (232-306) has a very strong chromatin binding affinity and thus is coined 'sticky-C' (StkC) (PubMed:19647732). StkC confers intranuclear immobility, but has no effect on subnuclear localization (PubMed:19647732). It is necessary for the interaction with IDM2 and IDM3, and for the anti-silencing function (PubMed:25684209). Methylated by PRMT11. DNA hypermethylation and transgene silencing phenotype.