Related Experiment Video
Updated: Jun 23, 2026
14:06
Mapping Bacterial Functional Networks and Pathways in Escherichia Coli using Synthetic Genetic Arrays
Published on: November 12, 2012
Conserved network of proteins essential for bacterial viability
Jennifer I Handford1, Bérengère Ize, Grant Buchanan
1Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom.
Journal of Bacteriology
|April 21, 2009
Summary
The essential bacterial genes yjeE, yeaZ, and ygjD are crucial for cell viability and proper DNA organization in Escherichia coli. Their disruption leads to significant ultrastructural changes, linking DNA metabolism to cell division.
Area of Science:
- Microbiology
- Molecular Biology
- Cell Biology
Background:
- The yjeE, yeaZ, and ygjD genes are highly conserved across bacteria, archaea, and eukaryotes.
- Orthologs of ygjD are found in Archaea and eukaryotes, indicating ancient functional importance.
Purpose of the Study:
- To investigate the essentiality and cellular functions of yjeE, yeaZ, and ygjD in Escherichia coli K12.
- To elucidate the interactions and regulatory roles of these conserved proteins in bacterial physiology.
Main Methods:
- Construction of conditional expression strains for yjeE, yeaZ, and ygjD in E. coli.
- Analysis of cell ultrastructure, nucleoid morphology, and DNA distribution under repressed expression.
- Complementation studies using the rstA gene and bacterial two-hybrid assays.
- In vitro proteolysis experiments to determine protein interactions and regulation.
Main Results:
- Each gene (yjeE, yeaZ, ygjD) was found to be essential for E. coli viability.
- Repression of gene expression caused distinct cellular defects, including condensed nucleoids and enlarged cells with peripheral DNA.
- rstA complemented all three conditional strains, suggesting involvement in a common pathway.
- YeaZ interacts with YjeE and YgjD, with a preference for YgjD, and YeaZ mediates YgjD proteolysis.
Conclusions:
- YjeE, YeaZ, and YgjD are essential components of a conserved bacterial pathway.
- These proteins likely form a regulatory complex linking DNA metabolism to cell division.
- YeaZ and YjeE regulate YgjD activity, potentially through proteolysis, impacting cell viability and structure.
Related Concept Videos
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...
01:23Stringent Response in E. coli
Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
01:29Coordination 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...
01:30Other 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...
01:26Bacterial Protein Maturation
Bacterial protein maturation is a tightly regulated process that ensures newly synthesized polypeptides achieve correct functional conformations. This maturation involves a series of modifications, folding events, and quality control steps, often assisted by specialized chaperone proteins.N-Terminal ModificationsThe maturation of bacterial polypeptides begins cotranslationally as the polypeptide exits the ribosome. The first amino acid, N-formylmethionine (fMet), is typically modified at the...
01:28Global 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...