N⁶-methyladenine modification of DNA enhances RecA-mediated homologous recombination.

ABSTRACT: Both DNA methylation and homologous recombination (HR) are extensively studied. In bacteria, Dam methylation is the most studied DNA modification, while RecA-mediated HR is a primary mechanism to repair DNA damages including double-stranded breaks, single-stranded gaps, and stalled replication forks. While HR regulation by proteins is extensively studied, whether methylation of DNA itself directly affects the functions of RecA and HR remains unclear. Mainly by single-molecule experiments, we report that Dam methylation of single-stranded DNA (ssDNA) promotes RecA assembly, partially by reducing the effective charge of ssDNA under counterion screening. Furthermore, Dam methylation of double-stranded DNA promotes homologous pairing, joint molecule growth, and strand exchange. In cellular exp

SUBMITTER: Zhao XC 

PROVIDER: S-EPMC12403123 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature