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Effects of condensing agent and nuclease on the extent of ejection from phage lambda

Evilevitch, Alex LU (2006) In The Journal of Physical Chemistry Part B 110(44). p.22261-22265
Abstract
We have recently demonstrated, that DNA ejection from bacteriophage I can be partially or completely suppressed in vitro by external osmotic pressure. This suggests that DNA ejection from phage is driven by an internal mechanical force consisting of DNA bending and DNA-DNA electrostatic repulsion energies. In the present work we investigate the extent to which DNA ejection is incomplete at zero osmotic external pressure when phage is opened with its receptor in vitro. The DNA fragment remaining in the capsid and the tail that is no longer bent or compressed sand hence for which there is no internal driving force for ejections is shown not to be ejected. We also demonstrate that DNA can be "pulled" out from the capsid by DNase I acting as a... (More)
We have recently demonstrated, that DNA ejection from bacteriophage I can be partially or completely suppressed in vitro by external osmotic pressure. This suggests that DNA ejection from phage is driven by an internal mechanical force consisting of DNA bending and DNA-DNA electrostatic repulsion energies. In the present work we investigate the extent to which DNA ejection is incomplete at zero osmotic external pressure when phage is opened with its receptor in vitro. The DNA fragment remaining in the capsid and the tail that is no longer bent or compressed sand hence for which there is no internal driving force for ejections is shown not to be ejected. We also demonstrate that DNA can be "pulled" out from the capsid by DNase I acting as a DNA binding protein or spermine acting as a DNA condensing agent. In particular, cryo electron microscopy and gel electrophoresis experiments show the following: (i) DNA ejection from bacteriophage I incubated in vitro with its receptor is incomplete at zero external osmotic force, with several persistence lengths of DNA remaining inside the phage capsid, if no nuclease ( DNase I) or DNA condensing agent ( spermine) is present in the host solution; (ii) in the presence of both DNase I and spermine in the host solution, 60% (approximate to 29 kbp) of wild-type lambda DNA (48.5 kbp) remains unejected inside the phage capsid, in the form of an unconstrained toroidal condensate; (iii) with DNase I added, but no spermine, the ejection is complete; (iv) with spermine, but without DNase I added, all the DNA is again ejected, and organized as a toroidal condensate outside. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
The Journal of Physical Chemistry Part B
volume
110
issue
44
pages
22261 - 22265
publisher
The American Chemical Society
external identifiers
  • wos:000241729300030
  • scopus:33751323827
ISSN
1520-5207
DOI
10.1021/jp060573j
language
English
LU publication?
yes
id
10776b3a-1a60-4b2d-b9d7-5a03fd25185c (old id 378321)
date added to LUP
2007-10-02 19:13:36
date last changed
2019-03-17 04:23:52
@article{10776b3a-1a60-4b2d-b9d7-5a03fd25185c,
  abstract     = {We have recently demonstrated, that DNA ejection from bacteriophage I can be partially or completely suppressed in vitro by external osmotic pressure. This suggests that DNA ejection from phage is driven by an internal mechanical force consisting of DNA bending and DNA-DNA electrostatic repulsion energies. In the present work we investigate the extent to which DNA ejection is incomplete at zero osmotic external pressure when phage is opened with its receptor in vitro. The DNA fragment remaining in the capsid and the tail that is no longer bent or compressed sand hence for which there is no internal driving force for ejections is shown not to be ejected. We also demonstrate that DNA can be "pulled" out from the capsid by DNase I acting as a DNA binding protein or spermine acting as a DNA condensing agent. In particular, cryo electron microscopy and gel electrophoresis experiments show the following: (i) DNA ejection from bacteriophage I incubated in vitro with its receptor is incomplete at zero external osmotic force, with several persistence lengths of DNA remaining inside the phage capsid, if no nuclease ( DNase I) or DNA condensing agent ( spermine) is present in the host solution; (ii) in the presence of both DNase I and spermine in the host solution, 60% (approximate to 29 kbp) of wild-type lambda DNA (48.5 kbp) remains unejected inside the phage capsid, in the form of an unconstrained toroidal condensate; (iii) with DNase I added, but no spermine, the ejection is complete; (iv) with spermine, but without DNase I added, all the DNA is again ejected, and organized as a toroidal condensate outside.},
  author       = {Evilevitch, Alex},
  issn         = {1520-5207},
  language     = {eng},
  number       = {44},
  pages        = {22261--22265},
  publisher    = {The American Chemical Society},
  series       = {The Journal of Physical Chemistry Part B},
  title        = {Effects of condensing agent and nuclease on the extent of ejection from phage lambda},
  url          = {http://dx.doi.org/10.1021/jp060573j},
  volume       = {110},
  year         = {2006},
}