329D

EFFECT OF CYTOSINE METHYLATION ON DNA-DNA RECOGNITION AT CPG STEPS

Summary for 329D

• Entry DOI: 10.2210/pdb329d/pdb
• Descriptor: DNA (5'-D(*AP*CP*CP*GP*CP*(5CM)P*GP*GP*CP*GP*CP*C)-3'), DNA (5'-D(*GP*GP*CP*GP*CP*(5CM)P*GP*GP*CP*GP*GP*T)-3') (3 entities in total)
• Functional Keywords: b-dna, double helix, dna
• Total number of polymer chains: 2
• Total formula weight: 7357.80

Authors

Mayer-Jung, C.,Moras, D.,Timsit, Y. (deposition date: 1997-04-29, release date: 1997-04-30, Last modification date: 2024-04-03)

Primary citation

Mayer-Jung, C.,Moras, D.,Timsit, Y.
Effect of cytosine methylation on DNA-DNA recognition at CpG steps.
J.Mol.Biol., 270:328-335, 1997

PubMed Abstract: Although DNA methylation is a fundamental mechanism for repressing genetic activity, the influence of methyl groups on DNA conformation is found to be small. In this study, the role of cytosine methylation is analysed in the context of DNA condensation by examining its influence on DNA-DNA recognition processes. Previously CpG sites were found to act as sequence determinants for the close and specific self-fit of B-DNA helices into cross-overs. In the present study, the crystal structure of the B-DNA dodecamer d(ACCGCCGGCGCC) methylated at its central CpG sequence shows that the methyl groups do not interfere with DNA self-fitting. In contrast, the two methyl groups form a clamp, which traps the incoming phosphate in the groove-backbone interaction. This geometry allows the formation of two new C-H...O hydrogen bonds between the methyl groups and the anionic oxygen atoms of the phosphate, which may further stabilize the interaction. This finding relates cytosine methylation to the formation of higher-order DNA structures and could provide new insights for understanding the mode of action of DNA methylation in genetic inactivation.

PubMed: 9237900
DOI: 10.1006/jmbi.1997.1137

Experimental method

X-RAY DIFFRACTION (2.7 Å)