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

Microorganisms

Véronique Arluison¹  Frederic Geinguenaud²  Rachna Shah³  MarisaA. Rivera³  MarkJ. Novak⁴  BrittanyA. Niccum⁵  ViraliJ. Parekh⁶  Frank Wien⁷  RichardR. Sinden⁸ 

[1] Inserm U1148, Laboratory for Vascular Translational Science, UFR SMBH, Université Paris 13, Sorbonne Paris Cité, F-93017 Bobigny, France;Rapid City, SD 57701, USA;Department of Biological Sciences, Florida Institute of Technology, Melbourne, FL 32901, USA;Department of Chemistry and Applied Biological Sciences, South Dakota School of Mines and Technology;Department of Mathematics, Florida Institute of Technology, Melbourne, FL 32901, USA;Laboratory of DNA Structure and Mutagenesis, Department of Chemistry and Applied Biological Sciences, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA;;Plateforme CNanoMat &Synchrotron SOLEIL, 91192 Gif-sur-Yvette, France;

关键词: genomic instability;    quadruplex;    dna;    mutagenesis;    nucleoid;    bacterial chromatin;   

DOI  :  10.3390/microorganisms8010028

来源: DOAJ

【 摘 要 】

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 blockage, promoting genomic instability. Furthermore, our results also evidence that the nucleoid-associated protein Hfq is involved in the genetic instability associated with these sequences. Hfq binds and stabilizes G-quadruplex structure in vitro and likely in cells. Collectively, our results thus implicate quadruplexes structures and Hfq nucleoid protein in the potential for genetic change that may drive evolution or alterations of bacterial gene expression.

【 授权许可】

Unknown