Related Experiment Video

Updated: Jul 15, 2025

Method for Efficient Refolding and Purification of Chemoreceptor Ligand Binding Domain
14:25

Method for Efficient Refolding and Purification of Chemoreceptor Ligand Binding Domain

Published on: December 12, 2017

18.0K

The importance of the PapR7 C-terminus and amide protons in mediating quorum sensing in Bacilluscereus

Michael Gorgan1, Shahar Vanunu Ofri2, Emilee R Engler3

  • 1Department of Chemistry, Lafayette College, 701 Sullivan Rd., Easton, PA 18042, United States.

Research in Microbiology
|September 27, 2023
PubMed

Insights

Researchers identified key molecular features of Bacillus cereus quorum sensing (QS) inhibitors. Modifications to the PapR7 peptide revealed that the C-terminal carboxylate and amide protons are crucial for effective QS inhibition, leading to new anti-infective strategies.

Area of Science:

  • Microbiology
  • Biochemistry
  • Drug Discovery

Background:

  • Bacillus cereus, an opportunistic pathogen, utilizes bacterial quorum sensing (QS) to regulate virulence factors.
  • The PlcR:PapR7 signaling pathway is central to B. cereus QS and represents a potential target for anti-infective therapies.
  • Previous QS inhibitor development focused on the C-terminal region of PapR7.

Purpose of the Study:

  • To investigate the role of C-terminal carboxylate and amide protons in PapR7-mediated QS activity.
  • To develop novel QS inhibitors targeting the PlcR:PapR7 interface.
  • To identify structure-activity relationships for B. cereus QS inhibitors.

Main Methods:

  • N-methyl scan of the PapR7 peptide.
  • C-terminal modification of existing B. cereus QS inhibitors.
  • β-galactosidase and hemolysis assays to assess QS inhibition.
  • Structure-activity relationship analysis.

Main Results:

  • The amide proton at Glu6 and the C-terminal carboxylate of PapR7 are critical for QS inhibition.
  • Several novel QS inhibitors were identified with nanomolar potency.
  • Structure-activity data provides insights into inhibitor design.

Conclusions:

  • The C-terminal modifications are essential for potent QS inhibition of the PlcR regulon in B. cereus.
  • Developed inhibitors and structure-activity data can guide the development of novel anti-infective strategies against B. cereus.
  • Targeting the PlcR:PapR7 interface offers a promising avenue for combating B. cereus infections.
Keywords:
Bacillus cereus groupPeptide structure–activity relationshipsPlcR antagonistsQuorum sensing

More Related Videos

Identification of Antibacterial Immunity Proteins in Escherichia coli using MALDI-TOF-TOF-MS/MS and Top-Down Proteomic Analysis09:26

Identification of Antibacterial Immunity Proteins in Escherichia coli using MALDI-TOF-TOF-MS/MS and Top-Down Proteomic Analysis

Published on: May 23, 2021

3.2K
Recombinant Protein Expression, Crystallization, and Biophysical Studies of a Bacillus-conserved Nucleotide Pyrophosphorylase, BcMazG12:23

Recombinant Protein Expression, Crystallization, and Biophysical Studies of a Bacillus-conserved Nucleotide Pyrophosphorylase, BcMazG

Published on: May 16, 2017

7.6K

Related Concept Videos

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,...
35
Bacterial Signaling01:30

Bacterial Signaling

Bacterial signaling can occur within bacteria (intracellular) or between bacteria (intercellular). At times, a group of bacteria behaves like a community. To achieve this, they engage in quorum sensing, the perception of higher cell density that causes changes in gene expression. Quorum sensing involves both extracellular and intracellular signaling. The signaling cascade starts with a molecule called an autoinducer (AI). Individual bacteria produce AIs that move out of the bacterial cell...
32.6K
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...
41
Prokaryotic Transcriptional Activators and Repressors01:58

Prokaryotic Transcriptional Activators and Repressors

The organization of prokaryotic genes in their genome is notably different from that of eukaryotes. Prokaryotic genes are organized, such that the genes for proteins involved in the same biochemical process or function are located together in groups. This group of genes, along with their regulatory elements, are collectively known as an operon. The functional genes in an operon are transcribed together to give a single strand of mRNA known as polycistronic mRNA.
Transcription of prokaryotic...
21.1K
Bacterial RNA Polymerase00:43

Bacterial RNA Polymerase

Unlike eukaryotes, bacteria use a single RNA Polymerase (RNAP) to transcribe all genes. The different subunits of bacterial RNAPhave distinct functions. The multisubunit structure of the bacterial RNAP helps the enzyme to maintain catalytic function, facilitate assembly, interact with DNA and RNA, and self-regulate its activity.
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
29.6K
Other Stress Responses in Bacteria01:30

Other Stress Responses in Bacteria

Bacteria have global regulatory systems that control several types of stress mechanisms. These include Pho regulon and the heat shock response, which are essential systems for environmental adaptation, such as nutrient limitation and proteotoxic stress. The Pho regulon and the heat shock response exemplify bacterial resilience, enabling rapid adaptation to fluctuating environmental conditions.Pho RegulonBacteria require phosphorus for essential cellular processes, including nucleic acid...
30