Related Experiment Video

Updated: Mar 21, 2026

In Vitro Directed Evolution of a Restriction Endonuclease with More Stringent Specificity
09:16

In Vitro Directed Evolution of a Restriction Endonuclease with More Stringent Specificity

Published on: March 25, 2020

7.8K

Regulation of genetic flux between bacteria by restriction-modification systems

Pedro H Oliveira1, Marie Touchon2, Eduardo P C Rocha2

  • 1Microbial Evolutionary Genomics, Institut Pasteur, 75015 Paris, France; CNRS, UMR 3525, 75015 Paris, France pcphco@gmail.com.

Proceedings of the National Academy of Sciences of the United States of America
|May 4, 2016
PubMed

Insights

Restriction-modification (R-M) systems, bacteria

Area of Science:

  • Microbiology
  • Genetics
  • Evolutionary Biology

Background:

  • Restriction-modification (R-M) systems function as bacterial innate immunity against mobile genetic elements (MGEs).
  • R-M system abundance correlates with MGE presence and has been linked to bacterial virulence.
  • R-M systems may promote genetic exchange by creating double-stranded DNA breaks.

Purpose of the Study:

  • To investigate whether R-M systems favor or disfavor genetic exchanges in bacteria.
  • To analyze the relationship between R-M system frequency, genome size, and genetic transfer events.
  • To develop a predictor for Type II R-M system recognition sites and assess its impact on genetic exchange.

Main Methods:

  • Analysis of R-M system frequency relative to homologous recombination and horizontal gene transfer events in 79 bacterial species.
  • Development of a recognition target motif predictor for Type II R-M systems.
  • Comparative genomic analysis to identify genomes with similar R-M system restriction sites.

Main Results:

  • Genetic exchanges were more frequent in bacteria with larger genomes and higher R-M system counts.
  • Genomes with similar R-M system recognition sites exhibited increased genetic exchange, irrespective of evolutionary distance.
  • R-M systems are more prevalent in genetically promiscuous bacteria, facilitating preferential gene transfer pathways.

Conclusions:

  • R-M systems are associated with increased genetic exchange, particularly between bacteria with compatible R-M systems.
  • The dynamic nature of R-M system repertoires leads to constantly shifting, time-dependent networks of bacterial gene transfer.
  • R-M systems play a complex role in bacterial evolution, influencing both defense and genetic diversification.
Keywords:
bacterial evolutionhomologous recombinationhorizontal gene transfer

More Related Videos

Inducing a Site Specific Replication Blockage in E. coli Using a Fluorescent Repressor Operator System11:19

Inducing a Site Specific Replication Blockage in E. coli Using a Fluorescent Repressor Operator System

Published on: August 21, 2016

9.6K
DNA-affinity-purified Chip DAP-chip Method to Determine Gene Targets for Bacterial Two component Regulatory Systems12:24

DNA-affinity-purified Chip DAP-chip Method to Determine Gene Targets for Bacterial Two component Regulatory Systems

Published on: July 21, 2014

17.4K

Related Concept Videos

Global Regulatory Systems01:28

Global Regulatory Systems

Global regulatory systems in bacteria enable rapid and coordinated responses to environmental changes by integrating sensory inputs with gene expression, ensuring efficient adaptation to fluctuating conditions. Key global regulatory mechanisms include regulons, two-component systems, sigma factors, and secondary messengers.Regulons and Global RegulatorsA regulon is a collection of genes and operons controlled by a common global regulator. These regulators enable bacteria to prioritize resource...
859
Restriction Enzymes01:11

Restriction Enzymes

Restriction enzymes are bacterial enzymes used to cut DNA in a sequence-specific manner. To cleave DNA, they bind to specific palindromic sequences called restriction sites. Such palindromic DNA sequences or inverted repeats are commonly found in regions of functional significance, such as the origin of replication, gene operator sites, and regions containing transcription termination signals.
The host bacteria protect their own genomic DNA from these enzymes by methylating these sites. Some...
38.5K
Regulation of Bacterial Virulence01:28

Regulation of Bacterial Virulence

Pathogenic bacteria employ a range of regulatory mechanisms to modulate the expression of virulence genes in response to environmental and host-derived signals. These mechanisms ensure that virulence factors are expressed only under favorable conditions, thereby optimizing infection and survival strategies.Mechanisms of Virulence RegulationKey regulatory strategies include:Two-Component Systems: These consist of a membrane-bound sensor kinase and a cytoplasmic response regulator. Environmental...
3
Coordination of Gene Expression Processes in Bacteria01:29

Coordination of Gene Expression Processes in Bacteria

The DNA replication, transcription, and translation processes are intricately coupled in bacteria, allowing efficient gene expression and rapid protein synthesis. While this physical and functional coordination is advantageous, it introduces challenges that bacteria overcome through specific regulatory mechanisms.Coupling of Replication, Transcription, and TranslationThe coupling of replication, transcription, and translation is a hallmark of bacterial gene expression. As the replisome unwinds...
846
Translational Regulation01:29

Translational Regulation

Translational regulation in prokaryotes ensures efficient protein synthesis by controlling ribosome access to mRNA. This regulation is mediated by secondary RNA structures, including translational riboswitches, RNA thermometers, and small RNAs (sRNAs), which respond to intracellular and environmental signals to modulate gene expression.Translational RiboswitchesRiboswitches in the leader region of mRNAs can regulate translation by altering the accessibility of the Shine-Dalgarno (SD) sequence,...
788
Gene Regulation in Microbial Communities: Quorum Sensing01:28

Gene Regulation in Microbial Communities: Quorum Sensing

Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,...
859