Related Experiment Video
Updated: Jul 7, 2026
06:33
Three-dimensional Imaging of Bacterial Cells for Accurate Cellular Representations and Precise Protein Localization
Published on: October 29, 2019
The different shapes of cocci
André Zapun1, Thierry Vernet, Mariana G Pinho
1Laboratoire d'Ingénierie des Macromolécules, Institut de Biologie Structurale (CEA/CNRS/UJF UMR5075), Grenoble, France.
FEMS Microbiology Reviews
|February 13, 2008
Summary
Bacterial shape, like round or ovoid cocci, is linked to cell wall construction. Different penicillin-binding proteins and peptidoglycan synthesis mechanisms influence cocci morphogenesis.
Area of Science:
- Microbiology
- Cell Biology
- Biochemistry
Background:
- Bacterial shape is determined by cell wall composition and structure.
- Cocci exhibit diverse morphologies, including spherical (staphylococci) and ovoid (streptococci) shapes.
- Penicillin-binding proteins (PBPs) are crucial enzymes involved in peptidoglycan synthesis and cell wall assembly.
Purpose of the Study:
- To review the relationship between cell wall synthesis mechanisms and bacterial cell shape determination in cocci.
- To integrate ultrastructural data with recent localization studies on PBPs.
- To clarify the differences in morphogenesis among various cocci genera.
Main Methods:
- Review of existing ultrastructural data.
- Analysis of recent PBP localization studies.
- Comparative analysis of peptidoglycan biosynthesis machineries.
Main Results:
- A correlation exists between bacterial shape and the set of PBPs.
- Spherical cocci (e.g., staphylococci) appear to utilize one peptidoglycan biosynthesis machinery.
- Ovoid cocci (e.g., streptococci) are proposed to have two distinct peptidoglycan synthesis machineries.
Conclusions:
- Differences in cell wall synthesis machinery contribute to the diverse shapes observed in cocci.
- Understanding these mechanisms provides insight into bacterial morphogenesis.
- Further research can clarify the precise roles of different PBPs in shaping cocci.
Related Concept Videos
01:29Microbial Morphologies
Bacterial and archaeal cells exhibit remarkable diversity in shape and structure, critical in their adaptability and functionality. Among bacteria, the most commonly observed shapes include cocci and bacilli. Cocci are spherical and may exist singly or in groupings such as pairs (diplococci), chains (streptococci), clusters (staphylococci), or tetrads. Bacilli, in contrast, are rod-shaped and can also occur as single cells, in pairs, or chains, depending on their environmental and genetic...
01:30Bacterial Phylum Actinobacteria
Coryneform bacteria are gram-positive, aerobic, nonmotile rods that exhibit irregular, club-shaped, or V-shaped arrangements. Their V-shape results from snapping division, where the inner cell wall layer forms the cross-wall, while the outer layer remains intact until it ruptures on one side, causing the daughter cells to bend away.The primary genera are Corynebacterium and Arthrobacter. Corynebacterium includes diverse species, ranging from saprophytes to pathogens like Corynebacterium...
01:18Molecular Shapes
Molecules have characteristic shapes that are crucial for their function. The arrangement of various electron groups around the central atom dictates their molecular geometry. Electron pairs in the valence shell of a central atom will adopt an arrangement that minimizes repulsions between the electron pairs by maximizing the distance between them. The valence electrons form either bonding pairs, located primarily between bonded atoms, or lone pairs.Two regions of electron density in a diatomic...
01:25Shape and Texture of Coarse Aggregate
Aggregate shape is classified based on the relative sharpness or roundness of the edges and corners. This classification includes categories like rounded, angular, elongated, and flaky, each with specific characteristics. Rounded aggregates, fully shaped by attrition, are typical of river or seashore gravel, while angular aggregates, such as crushed rock, have well-defined edges. Aggregates that are elongated and flaky are less desirable, as they can reduce the workability and strength of...
01:29Cytoskeletal 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...
01:13Cell Diversity
The concept of a cell started with microscopic observations of dead cork tissue by Robert Hooke in 1665. Hooke coined the term "cell" based on the resemblance of the small subdivisions in the cork to the rooms that monks inhabited, called cells. About ten years later, Antonie van Leeuwenhoek became the first person to observe the living and moving cells under a microscope. In the century that followed, the theory that cells represented the basic unit of life developed.
Multicellular organisms...
Multicellular organisms...