Related Experiment Video
Updated: Jul 13, 2026
06:10
Following Cell-fate in E. coli After Infection by Phage Lambda
Published on: October 14, 2011
Structure of bacteriophage SPP1 tail reveals trigger for DNA ejection
Celia Plisson1, Helen E White, Isabelle Auzat
1School of Crystallography, Birkbeck College, University of London, London, UK.
The EMBO Journal
|July 6, 2007
Summary
Bacteriophage SPP1 tail structures reveal a domino-like cascade mechanism for DNA ejection. Adsorption triggers tail tube rearrangements, enabling genome delivery into host cells.
Area of Science:
- Molecular Biology
- Structural Biology
- Virology
Background:
- Bacteriophages, viruses that infect bacteria, often possess long, noncontractile tails (Siphoviridae) for genome delivery.
- The tail's adsorption device initiates host cell recognition and triggers DNA release.
Purpose of the Study:
- To elucidate the structural mechanisms underlying bacteriophage SPP1 DNA ejection.
- To understand how tail-receptor interactions lead to genome release.
Main Methods:
- Determined the structures of the bacteriophage SPP1 tail before and after DNA ejection.
- Analyzed structural rearrangements within the tail tube.
Main Results:
- Observed extensive structural rearrangements in the internal tail tube wall.
- Proposed a domino-like conformational cascade initiated by receptor binding.
- Identified signal propagation along the tail to the head-to-tail connector.
Conclusions:
- The adsorption device-receptor interaction triggers a conformational switch.
- This switch propagates along the tail, opening the head-to-tail connector for DNA ejection.
- The helical tail structure acts as a conduit for genome delivery into the host cell.
Related Concept Videos
01:26DNA 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...
01:30Lytic 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...
01:20Viral 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...
00:43Lysogenic 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...
00:56Viral Structure
Viruses are extraordinarily diverse in shape and size, but they all have several structural features in common. All viruses have a core that contains a DNA- or RNA-based genome. The core is surrounded by a protective coat of proteins called the capsid. The capsid is composed of subunits called capsomeres. The capsid and genome-containing core are together known as the nucleocapsid.
01:16Viral 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...