Virgile Viasnoff

Time lapse determination of DNA ejection from a bacteriophage T5. The ejection display pauses that we attribute to rearragement of DNA inside the capsid

Abstract:

Bacteriophage T5 DNA ejection is a complex process that occurs on several time scales in vitro. Using a combination of bulk and single phage measurements we quantitatively study the three steps of the ejection: binding to the host receptor, channel opening step and DNA release. Each step is separately addressed and its kinetics parameters evaluated. We reconstruct the bulk kinetics from the distribution of single phage events following individual DNA molecules with unprecedented time resolution. We show that at the single phage level the ejection kinetics of the DNA happens by rapid transient bursts that are not correlated to any genome sequence defects. We speculate that these transient pauses are due to local phase transitions of the DNA inside the capsid. We predict that such pauses should be seen for other phages with similar DNA packing ratio.