Related Experiment Video

Updated: Aug 25, 2026

Biochemical and Structural Characterization of the Carbohydrate Transport Substrate-binding-protein SP0092
08:53

Biochemical and Structural Characterization of the Carbohydrate Transport Substrate-binding-protein SP0092

Published on: October 2, 2017

The D,D-carboxypeptidase PBP3 organizes the division process of Streptococcus pneumoniae

Cécile Morlot1, Marjolaine Noirclerc-Savoye, André Zapun

  • 1Laboratoire d'Ingénierie des Macromolécules, Institut de Biologie Structurale J-P Ebel (CEA/CNRS/UJF, UMR 5075), 41 rue Jules Horowitz, 38027 Grenoble Cedex 1, France.

Molecular Microbiology
|March 11, 2004
PubMed

Insights

Bacterial cell division relies on coordinating membrane invagination and cell wall synthesis. PBP3 is crucial for this coordination, ensuring proper localization of high-molecular-weight penicillin-binding proteins (HMW PBPs) during division.

Area of Science:

  • Microbiology
  • Cell Biology
  • Biochemistry

Background:

  • Bacterial division involves coordinated FtsZ-ring constriction and cell wall synthesis by high-molecular-weight penicillin-binding proteins (HMW PBPs).
  • The precise mechanisms coordinating these two essential processes remain incompletely understood.

Purpose of the Study:

  • To investigate the role of PBP3 in coordinating bacterial cell division in Streptococcus pneumoniae.
  • To elucidate the relationship between PBP3, HMW PBPs, FtsZ, and FtsW localization during cell division.

Main Methods:

  • Immunofluorescence microscopy was employed to visualize the localization of key division proteins.
  • Analysis of a Streptococcus pneumoniae mutant lacking PBP3 was performed.

Main Results:

  • PBP3, a D,D-carboxypeptidase, is essential for the co-localization of HMW PBPs and FtsZ rings during cell division.
  • In PBP3-deficient mutants, HMW PBPs fail to localize correctly, disrupting the coordination of cell wall synthesis with FtsZ-ring constriction.
  • FtsW localization remains coordinated with FtsZ even in the absence of PBP3, suggesting distinct regulatory roles.

Conclusions:

  • Peptidoglycan composition, regulated by PBP3 activity, is central to coordinating bacterial cell division.
  • The study reveals unexpected complexity in the interactions among bacterial division proteins.
  • PBP3's role highlights the importance of substrate availability in directing HMW PBP localization for proper cell division.

More Related Videos

Live Cell Imaging of Bacillus subtilis and Streptococcus pneumoniae using Automated Time-lapse Microscopy07:31

Live Cell Imaging of Bacillus subtilis and Streptococcus pneumoniae using Automated Time-lapse Microscopy

Published on: July 28, 2011

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

Related Concept Videos

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...
Cytoskeletal Proteins in Bacteria01:29

Cytoskeletal Proteins in Bacteria

Bacterial cells were initially considered simple, randomly organized structures lacking a cytoskeleton. However, the discovery of cytoskeleton homologs in bacteria led to the change of this opinion. Bacterial cytoskeletal filaments regulate the cell shape, cell polarity, cell division, and partitioning of plasmids during cell division. It was later discovered that bacterial cytoskeletal proteins, mainly actin and tubulin homologs, are diverse compared to their eukaryotic counterparts. On the...
Formation of Lipopolysaccharides01:19

Formation of Lipopolysaccharides

Lipopolysaccharides (LPS) are crucial components of the outer membrane of Gram-negative bacteria, serving both structural and functional roles. It contributes to membrane stability and protects bacteria from host immune responses. LPS is composed of three major regions—lipid A, a core oligosaccharide, and an O antigen. The biosynthesis and assembly of LPS involve a highly coordinated set of enzymatic reactions and transport mechanisms. Additionally, LPS is recognized as an endotoxin, triggering...
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...
Bacterial Phylum Proteobacteria01:26

Bacterial Phylum Proteobacteria

Proteobacteria, one of the largest and most diverse bacterial phyla, encompasses a wide range of Gram-negative bacteria distinguished by their outer membrane composed of lipopolysaccharides. These microorganisms exhibit various metabolic capabilities, including phototrophy, chemolithotrophy, and heterotrophy, and thrive in diverse environments from soil to aquatic systems and host-associated niches. The phylum is divided into six classes: Alphaproteobacteria, Betaproteobacteria,...
Inhibitors of Gram-positive Cell Wall Synthesis01:23

Inhibitors of Gram-positive Cell Wall Synthesis

Bacterial cell walls are typically rigid structures composed mainly of peptidoglycan, a mesh-like polymer that provides mechanical strength and maintains cell shape. The synthesis of peptidoglycan is a crucial process in bacterial growth and serves as a primary target for many antibiotics.Mechanism of Action of Beta-Lactam AntibioticsBeta-lactam antibiotics, such as penicillin, inhibit peptidoglycan synthesis in actively growing cells. These antibiotics share a characteristic four-membered...