Role of Hfq in Genome Evolution: Instability of G-Quadruplex Sequences in E. coli.

ABSTRACT: Certain G-rich DNA repeats can form quadruplex in bacterial chromatin that can present blocks to DNA replication and, if not properly resolved, may lead to mutations. To understand the participation of quadruplex DNA in genomic instability in Escherichia coli (E. coli), mutation rates were measured for quadruplex-forming DNA repeats, including (G3T)4, (G3T)8, and a RET oncogene sequence, cloned as the template or nontemplate strand. We evidence that these alternative structures strongly influence mutagenesis rates. Precisely, our results suggest that G-quadruplexes form in E. coli cells, especially during transcription when the G-rich strand can be displaced by R-loop formation. Structure formation may then facilitate replication misalignment, presumably associated with replication fork bl

SUBMITTER: Parekh VJ 

PROVIDER: S-EPMC7023247 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature