A Single-Molecule Hershey-Chase Experiment

  title={A Single-Molecule Hershey-Chase Experiment},
  author={David A. Van Valen and David Wu and Yi-Ju Chen and Hannah H Tuson and Paul A. Wiggins and Rob Phillips},
  journal={Current Biology},

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Two-Stage Dynamics of in Vivo Bacteriophage Genome Ejection

It is proposed that, after an initial phase driven by self-repulsion of DNA in the capsid, the ejection is driven by anomalous diffusion of phageDNA in the crowded bacterial cytoplasm, and it is expected that this two-step mechanism is general for phages that operate by pressure-driven ejection.

Popping the cork: mechanisms of phage genome ejection

The structure of the DNA inside mature phages is described and the current models of genome ejection, both in vitro and in vivo, are summarized.

Capstan friction model for DNA ejection from bacteriophages.

A mechanical model is proposed that is able to explain the observed dependence of exit velocity on ejected length, and that is also consistent with the accepted picture of the geometric arrangement of DNA within the viral capsid.

Forced phage uncorking: viral DNA ejection triggered by a mechanically sensitive switch.

It is shown that tapping the capsid wall with an oscillating atomic-force-microscope cantilever triggers rapid DNA ejection via the tail complex in single mature T7 phage particles, suggesting that the triggering process might involve a conformational switch that can be mechanically activated either by external forces or via the Tail-fiber complex.

Dissecting the Operating Mechanism of a Biological Motor One Molecule at a Time

The first comprehensive mechanochemical characterization of a homomeric ring ATPase - Phi29 gp16 - which translocates dsDNA in cycles composed of alternating dwells and bursts is presented, revealing a high degree of coordination among ring subunits and showing an unexpected division of labor.

Dynamic Measurements of the Position, Orientation, and DNA Content of Individual Unlabeled Bacteriophages.

The use of holographic microscopy is demonstrated to track the position, orientation, and DNA content of unlabeled bacteriophages (phages) in solution near a planar, functionalized glass surface and finds that under certain conditions, λ phages move along the surface with their heads down and intermittently stick to the surface by their tails, causing them to stand up.

Langevin dynamics simulation of DNA ejection from a phage

The Langevin dynamics simulations of a coarse-grained model of ejection of dsDNA from Φ29 phage show the nonergodic nature of the ejection kinetics and call for better theoretical models to portray the kinetics of genome ejection from phages.

The mobility of packaged phage genome controls ejection dynamics

In vitro study reveals that DNA ejection dynamics for phages can be synchronized or desynchronized based on mobility of encapsidated DNA, which in turn is regulated by environmental factors, such as temperature and extra-cellular ionic conditions.

Location of the unique integration site on an Escherichia coli chromosome by bacteriophage lambda DNA in vivo

It is shown that λ DNA remains confined near the entry point of a cell following infection, and the encounter between the 15-bp-long target sequence on the chromosome and the recombination site on the viral genome is facilitated by the directed motion of bacterial DNA generated during chromosome replication, in conjunction with constrained diffusion of phage DNA.



Real-time observations of single bacteriophage λ DNA ejections in vitro

Real-time measurements of ejection from phage λ are reported, revealing how the speed depends on key physical parameters such as genome length and ionic state of the buffer.

Real-time observations of single bacteriophage lambda DNA ejections in vitro.

Real-time measurements of ejection from phage lambda are reported, revealing how the speed depends on key physical parameters such as genome length and ionic state of the buffer.

Real-Time Imaging of DNA Ejection from Single Phage Particles

No syringes please, ejection of phage T7 DNA from the virion is enzyme driven

Current data suggest a highly speculative model, in which two of the proteins ejected from the phages head establish a molecular motor that ratchets the phage genome into the cell.

The effect of genome length on ejection forces in bacteriophage lambda.

Dynamics of DNA ejection from bacteriophage.

The results suggest a series of in vitro experiments involving the ejection of DNA into vesicles filled with varying amounts of binding proteins from phage whose state of stress is controlled by ambient salt conditions or by tuning genome length.

Bacteriophage T7 DNA ejection into cells is initiated by an enzyme‐like mechanism

The data are consistent with the idea that transcription‐independent DNA translocation from the T7 virion is also enzyme‐catalysed, and the proton motive force is necessary for this mode of DNA translocated.