DNA Methylation and RNA-DNA Hybrids Regulate the Single-Molecule Localization of a DNA Methyltransferase on the Bacterial Nucleoid.

Bacterial DNA methyltransferases (MTases) function in restriction modification systems, cell cycle control, and the regulation of gene expression. DnmA is a recently described DNA MTase that forms N6-methyladenosine at nonpalindromic 5'-GACGG-3' sites in Bacillus subtilis, yet how DnmA activity is regulated is unknown. To address DnmA regulation, we tested substrate binding and found that DnmA binds poorly to methylated DNA and to an RNA-DNA hybrid with the DNA recognition sequence.