Related Experiment Video

Updated: Jun 30, 2026

Following Cell-fate in E. coli After Infection by Phage Lambda
06:10

Following Cell-fate in E. coli After Infection by Phage Lambda

Published on: October 14, 2011

The lysis system of the Streptomyces aureofaciens phage mu1/6

Jarmila Farkasovská1, Andrej Godány

  • 1Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, Slovakia. jarmila.farkasovska@savba.sk

Current Microbiology
|September 26, 2008
PubMed

Insights

Phage mu1/6 holin and endolysin genes were cloned and expressed in E. coli. Holin function was demonstrated in streptomycetes, showing its role in membrane lesion formation for phage lysis.

Area of Science:

  • Bacteriophage biology
  • Molecular genetics
  • Microbial lysis mechanisms

Background:

  • The lysis module of bacteriophage mu1/6 contains genes essential for host cell destruction.
  • Two genes, lyt and hol, were previously identified. A third candidate, hol2, was found downstream of hol.
  • Holin proteins are known to permeabilize the cytoplasmic membrane, facilitating endolysin activity.

Purpose of the Study:

  • To characterize the function of the newly identified holin gene, hol2, from phage mu1/6.
  • To investigate the lytic activity of phage mu1/6 holins in conjunction with endolysins in Escherichia coli.
  • To demonstrate holin-mediated membrane permeabilization in a heterologous host, Streptomyces.

Main Methods:

  • Cloning and expression of phage mu1/6 genes (lyt, hol, hol2) in Escherichia coli.
  • Coexpression of endolysin and holin genes to assess cell lysis.
  • Assessing holin function in Streptomyces by monitoring endolysin release and peptidoglycan hydrolysis.

Main Results:

  • Expression of either hol or hol2 in E. coli induced cell death.
  • Coexpression of mu1/6 holin and endolysin (lambdaR or mu1/6 lyt) resulted in E. coli cell lysis.
  • Coexpression of mu1/6 hol2 with endolysins did not lead to detectable lysis.
  • Holin function was confirmed in Streptomyces, where it facilitated endolysin release and peptidoglycan cleavage, indicating membrane lesion formation.

Conclusions:

  • Phage mu1/6 holin is functional in E. coli and mediates cell lysis in concert with endolysin.
  • The hol2 gene product likely does not function as a holin or requires specific conditions not met in this study.
  • Phage mu1/6 holin can induce membrane lesions in Streptomyces, enabling phage-mediated lysis in this genus.

More Related Videos

Methodology for the Study of Horizontal Gene Transfer in Staphylococcus aureus10:39

Methodology for the Study of Horizontal Gene Transfer in Staphylococcus aureus

Published on: March 10, 2017

Time-Lapse Epifluorescence Microscopy Imaging of Pseudomonas aeruginosa and Staphylococcus aureus Heterogeneous Phenotypes07:44

Time-Lapse Epifluorescence Microscopy Imaging of Pseudomonas aeruginosa and Staphylococcus aureus Heterogeneous Phenotypes

Published on: February 14, 2025

Related Concept Videos

DNA Bacteriophages01:26

DNA Bacteriophages

Bacteriophages, or phages, are viruses that specifically infect bacteria, utilizing their genetic material to hijack host cellular machinery for replication. DNA bacteriophages employ single-stranded DNA (ssDNA) or double-stranded DNA (dsDNA) genomes. These phages exhibit diverse replication strategies and host interactions, influencing their ecological roles and applications in biotechnology and medicine.ssDNA BacteriophagesssDNA phages, with their small genomes, utilize unique strategies to...
Viral Replication: Lytic Cycle01:20

Viral Replication: Lytic Cycle

Bacteriophages, or phages, are viruses that specifically infect bacteria. Among them, T-even bacteriophages, such as T4, exhibit a well-characterized lytic replication cycle in Escherichia coli (E. coli). This process ensures the rapid proliferation of the virus while ultimately leading to the destruction of the bacterial host.Attachment and DNA InjectionThe infection process begins with the recognition and binding of the T4 phage to the E. coli cell surface. Tail fibers of the phage...
Viral Replication: Lysogenic Cycle01:16

Viral Replication: Lysogenic Cycle

The lysogenic cycle is a crucial viral replication strategy that allows bacteriophages to persist within host cells without immediately destroying them. This process is primarily observed in temperate phages, such as bacteriophage lambda (λ), which infects Escherichia coli. The cycle allows the viral genome to persist across bacterial generations while keeping host cells viable.Integration of the Viral GenomeUpon infection, bacteriophage lambda attaches to the bacterial surface and injects its...
Lytic Cycle of Bacteriophages01:30

Lytic Cycle of Bacteriophages

Bacteriophages, also known as phages, are specialized viruses that infect bacteria. A key characteristic of phages is their distinctive “head-tail” morphology. A phage begins the infection process (i.e., lytic cycle) by attaching to the outside of a bacterial cell. Attachment is accomplished via proteins in the phage tail that bind to specific receptor proteins on the outer surface of the bacterium. The tail injects the phage’s DNA genome into the bacterial cytoplasm. In the lytic replication...
Lysogenic Cycle of Bacteriophages00:43

Lysogenic Cycle of Bacteriophages

In contrast to the lytic cycle, phages infecting bacteria via the lysogenic cycle do not immediately kill their host cell. Instead, they combine their genome with the host genome, allowing the bacteria to replicate the phage DNA along with the bacterial genome. The incorporated copy of the phage genome is called the prophage. Some prophages can re-activate and enter the lytic cycle. This often occurs in response to a perturbation, such as DNA damage, but can also transpire in the absence of...
Bacteriophages of the Human Virome01:23

Bacteriophages of the Human Virome

Bacteriophages are found throughout the human body. They may even outnumber eukaryotic viruses, forming an important and dynamic component of the human virome. Indeed, phages represent the most abundant viral entities, with densities in the gut reaching up to 10⁹ particles per gram of fecal matter, and many belonging to orders such as Caudovirales and Microviridae, while a substantial proportion remains unclassified as viral “dark matter.”Lysogeny and Genetic ExchangeIn the gut, bacteriophages...