1NGN

Mismatch repair in methylated DNA. Structure of the mismatch-specific thymine glycosylase domain of methyl-CpG-binding protein MBD4

Summary for 1NGN

• Entry DOI: 10.2210/pdb1ngn/pdb
• Descriptor: methyl-CpG binding protein MBD4 (2 entities in total)
• Functional Keywords: mismacth repair in methylated dna, dna binding protein
• Biological source: Mus musculus (house mouse)
• Cellular location: Nucleus : Q9Z2D7
• Total number of polymer chains: 1
• Total formula weight: 18567.40

Authors

Wu, P.,Qiu, C.,Sohail, A.,Zhang, X.,Bhagwat, A.S.,Cheng, X. (deposition date: 2002-12-17, release date: 2003-03-18, Last modification date: 2024-02-14)

Primary citation

Wu, P.,Qiu, C.,Sohail, A.,Zhang, X.,Bhagwat, A.S.,Cheng, X.
Mismatch repair in methylated DNA. Structure and activity of the mismatch-specific thymine glycosylase domain of methyl-CpG-binding protein MBD4
J.Biol.Chem., 278:5285-5291, 2003

PubMed Abstract: MBD4 is a member of the methyl-CpG-binding protein family. It contains two DNA binding domains, an amino-proximal methyl-CpG binding domain (MBD) and a C-terminal mismatch-specific glycosylase domain. Limited in vitro proteolysis of mouse MBD4 yields two stable fragments: a 139-residue fragment including the MBD, and the other 155-residue fragment including the glycosylase domain. Here we show that the latter fragment is active as a glycosylase on a DNA duplex containing a G:T mismatch within a CpG sequence context. The crystal structure confirmed the C-terminal domain is a member of the helix-hairpin-helix DNA glycosylase superfamily. The MBD4 active site is situated in a cleft that likely orients and binds DNA. Modeling studies suggest the mismatched target nucleotide will be flipped out into the active site where candidate residues for catalysis and substrate specificity are present.

PubMed: 12456671
DOI: 10.1074/jbc.M210884200

Experimental method

X-RAY DIFFRACTION (2.1 Å)