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Updated: Jul 6, 2026
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T4 Bacteriophage and E. coli Interaction in the Murine Intestine: A Prototypical Model for Studying Host-Bacteriophage Dynamics In Vivo
Published on: January 26, 2024
Cryo-EM structures of phage T4 infection intermediate.
Qianqian Shao1, Junhua Dong2, Aohan Wang1
1School of Public Health (Shenzhen), Sun Yat-sen University, Shenzhen, Guangdong, China.
Journal of Molecular Biology
|July 4, 2026
Summary
We revealed the structure of a key intermediate in myophage T4 infection, uncovering how its tail machinery delivers viral DNA into host cells. This provides new insights into bacteriophage genome delivery mechanisms.
Area of Science:
- Structural biology
- Molecular biology
- Virology
Background:
- Bacteriophages, like myophage T4, possess complex contractile tails for host infection.
- Mechanisms of host recognition, signal transduction, and genome delivery by myophages are not fully understood.
Purpose of the Study:
- To elucidate the structural mechanisms underlying myophage T4 genome delivery.
- To characterize a pre-genome-release intermediate of myophage T4.
Main Methods:
- Cryo-electron microscopy (cryo-EM) was used to determine the structure of the myophage T4 intermediate.
- Comparative structural analysis was performed between different T4 virion states.
Main Results:
- The structure of a tail-contracted, pre-genome-release intermediate was determined.
- Structural transitions in the tail, tape-measure protein (TMP), baseplate, and long tail fibers were identified.
- Tail sheath contraction was found to be coupled with repositioning of the viral DNA-TMP complex, facilitating genome translocation.
Conclusions:
- The study reveals key structural dynamics driving myophage T4 genome delivery.
- Expelled TMP may form a transmembrane complex to aid genome translocation into the host cytosol.
- Findings advance understanding of bacteriophage infection machinery and DNA delivery processes.
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