Related Experiment Video

Updated: May 15, 2026

Synthesis of Masarimycin, a Small Molecule Inhibitor of Gram-Positive Bacterial Growth
09:10

Synthesis of Masarimycin, a Small Molecule Inhibitor of Gram-Positive Bacterial Growth

Published on: January 7, 2022

Phosphorylation of the Streptococcus pneumoniae cell wall biosynthesis enzyme MurC by a eukaryotic-like Ser/Thr

Shaun P Falk1, Bernard Weisblum

  • 1Department of Medicine, University of Wisconsin-Madison, School of Medicine and Public Health, Madison, WI 53706, USA.

FEMS Microbiology Letters
|January 3, 2013
PubMed

Insights

Streptococcus pneumoniae

Area of Science:

  • Microbiology
  • Biochemistry
  • Molecular Biology

Background:

  • Streptococcus pneumoniae possesses a unique Ser/Thr kinase-phosphatase pair, StkP-PhpP.
  • Cell wall peptidoglycan biosynthesis is crucial for bacterial survival and is a target for antibiotics.

Purpose of the Study:

  • To investigate the interaction between the StkP-PhpP system and MurC, an enzyme in peptidoglycan synthesis.
  • To elucidate the regulatory role of StkP-PhpP in cell wall biosynthesis.

Main Methods:

  • Combinatorial phage display was employed to identify interacting partners of StkP.
  • Enzyme-linked immunosorbent assay (ELISA) was used to confirm interactions.
  • Phosphorylation and dephosphorylation assays were performed to study enzyme activity.

Main Results:

  • A peptide sequence YEVCGSDTVGC, identified via phage display, was found to interact with StkP.
  • This peptide sequence showed high homology to a motif in Streptococcus pneumoniae MurC.
  • MurC was confirmed to be phosphorylated by StkP and dephosphorylated by PhpP.

Conclusions:

  • The StkP-PhpP kinase-phosphatase pair interacts with MurC, a key enzyme in cell wall peptidoglycan synthesis.
  • This interaction suggests a regulatory link between StkP-PhpP and the coordinated biosynthesis of the bacterial cell wall.

More Related Videos

Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/4306:06

Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/43

Published on: September 11, 2020

Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria11:32

Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria

Published on: February 23, 2014

Related Concept Videos

PI3K/mTOR/AKT Signaling Pathway01:22

PI3K/mTOR/AKT Signaling Pathway

The mammalian target of rapamycin  (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1  (mTORC1) and mTOR complex 2  (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast,  mTORC2 consists of a rapamycin-insensitive companion...
cAMP-dependent Protein Kinase Pathways01:25

cAMP-dependent Protein Kinase Pathways

Cyclic Adenosine Monophosphate (cAMP) is an essential second messenger that activates protein kinase A (PKA) and regulates various biological processes. A single epinephrine molecule binds to GPCR and activates several heterotrimeric G proteins, each stimulating multiple adenylyl cyclase, amplifying the signal, and synthesizing large numbers of cAMP molecules. Small changes in cAMP concentration affect PKA activity. The binding of four cAMP molecules induces a conformational change in PKA,...
Phosphorylation01:02

Phosphorylation

The addition or removal of phosphate groups from proteins is the most common chemical modification that regulates cellular processes. These modifications can affect the structure, activity, stability, and localization of proteins within cells as well as their interactions with other proteins.
During phosphorylation, protein kinases transfer the terminal phosphate group of ATP to specific amino acid side chains of substrate proteins. Serine, threonine, and tyrosine are the most commonly...
Peptidoglycan Synthesis01:28

Peptidoglycan Synthesis

Structure of PeptidoglycanPeptidoglycan is a vital structural component of the bacterial cell wall, providing mechanical strength and shape to the cell. It consists of repeating units of two sugars—N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM)—linked by β-1,4 glycosidic bonds. These sugar chains are cross-linked by short peptide chains, forming a mesh-like polymer that surrounds the bacterial plasma membrane.Cytoplasmic Phase – Precursor SynthesisPeptidoglycan biosynthesis begins in...
Gene Regulation During Sporulation01:17

Gene Regulation During Sporulation

Sporulation is a complex developmental process that allows certain Gram-positive bacteria, such as Bacillus subtilis and Clostridium species, to survive extreme environmental conditions. This process is tightly regulated by a series of signaling cascades and transcriptional controls, ensuring the formation of a highly resistant endospore.Sporulation is triggered by unfavorable conditions, such as nutrient depletion, and is governed by a phosphorelay system. One of the sensor kinases, such as...
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...