CH···O Hydrogen Bonds Mediate Highly Specific Recognition of Methylated CpG Sites by the Zinc Finger Protein Kaiso.

ABSTRACT: Many eukaryotic transcription factors recognize the epigenetic marker 5-methylcytosine (mC) at CpG sites in DNA. Despite their structural diversity, methyl-CpG-binding proteins (MBPs) share a common mode of recognition of mC methyl groups that involves hydrophobic pockets and weak hydrogen bonds of the CH···O type. The zinc finger protein Kaiso possesses a remarkably high specificity for methylated over unmethylated CpG sites. A key contribution to this specificity is provided by glutamate 535 (E535), which is optimally positioned to form multiple interactions with mCpG, including direct CH···O hydrogen bonds. To examine the role of E535 and CH···O hydrogen bonding in the preferential recognition of mCpG sites, we determined the structures of wild type Kaiso (WT) and E535 mutants and chara

SUBMITTER: Nikolova EN 

PROVIDER: S-EPMC5893398 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature