Structural insights into gene silencing

	The BAH1, BAH2, and methyltransferase domain are colored in light pink, orange, and cyan, respectively; DNA is in tan. Click here for more information.

A new study sheds light on the interaction between DNA and the enzyme that maintains DNA methylation, a process in which chemical changes to DNA influence and even silence a gene’s expression. The maintenance of certain methylation patterns across cell generations is carried out by the enzyme DNMT1. Jikui Song and colleagues have determined the crystal structure of mouse DNMT1 bound to a DNA duplex containing a partially methylated site on the parental strand, as would be found immediately after DNA replication. The results show how DNMT1 flips the target cytosine base of the DNA into the enzyme’s catalytic pocket.

Article #12: "Structure-Based Mechanistic Insights into DNMT1-Mediated Maintenance DNA Methylation," by J. Song; M. Teplova; S. Ishibe-Murakami; D.J. Patel at Memorial Sloan-Kettering Cancer Center in New York, NY; J. Song at University of California, Riverside in Riverside, CA.