1xyr
From Proteopedia
(New page: 200px<br /><applet load="1xyr" size="450" color="white" frame="true" align="right" spinBox="true" caption="1xyr" /> '''Poliovirus 135S cell entry intermediate'''<b...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1xyr.gif|left|200px]]<br /><applet load="1xyr" size=" | + | [[Image:1xyr.gif|left|200px]]<br /><applet load="1xyr" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1xyr" /> | caption="1xyr" /> | ||
'''Poliovirus 135S cell entry intermediate'''<br /> | '''Poliovirus 135S cell entry intermediate'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Poliovirus provides a well-characterized system for understanding how | + | Poliovirus provides a well-characterized system for understanding how nonenveloped viruses enter and infect cells. Upon binding its receptor, poliovirus undergoes an irreversible conformational change to the 135S cell entry intermediate. This transition involves shifts of the capsid protein beta barrels, accompanied by the externalization of VP4 and the N terminus of VP1. Both polypeptides associate with membranes and are postulated to facilitate entry by forming a translocation pore for the viral RNA. We have calculated cryo-electron microscopic reconstructions of 135S particles that permit accurate placement of the beta barrels, loops, and terminal extensions of the capsid proteins. The reconstructions and resulting models indicate that each N terminus of VP1 exits the capsid though an opening in the interface between VP1 and VP3 at the base of the canyon that surrounds the fivefold axis. Comparison with reconstructions of 135S particles in which the first 31 residues of VP1 were proteolytically removed revealed that the externalized N terminus is located near the tips of propeller-like features surrounding the threefold axes rather than at the fivefold axes, as had been proposed in previous models. These observations have forced a reexamination of current models for the role of the 135S particle in transmembrane pore formation and suggest testable alternatives. |
==About this Structure== | ==About this Structure== | ||
| - | 1XYR is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Human_poliovirus_1 Human poliovirus 1]. Full crystallographic information is available from [http:// | + | 1XYR is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Human_poliovirus_1 Human poliovirus 1]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XYR OCA]. |
==Reference== | ==Reference== | ||
| Line 13: | Line 13: | ||
[[Category: Human poliovirus 1]] | [[Category: Human poliovirus 1]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
| - | [[Category: Belnap, D | + | [[Category: Belnap, D M.]] |
[[Category: Bubeck, D.]] | [[Category: Bubeck, D.]] | ||
[[Category: Cheng, N.]] | [[Category: Cheng, N.]] | ||
| - | [[Category: Filman, D | + | [[Category: Filman, D J.]] |
| - | [[Category: Hogle, J | + | [[Category: Hogle, J M.]] |
| - | [[Category: Steven, A | + | [[Category: Steven, A C.]] |
[[Category: beta barrel]] | [[Category: beta barrel]] | ||
[[Category: cell entry intermediate]] | [[Category: cell entry intermediate]] | ||
| Line 24: | Line 24: | ||
[[Category: viral capsid]] | [[Category: viral capsid]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:00:02 2008'' |
Revision as of 14:00, 21 February 2008
|
Poliovirus 135S cell entry intermediate
Overview
Poliovirus provides a well-characterized system for understanding how nonenveloped viruses enter and infect cells. Upon binding its receptor, poliovirus undergoes an irreversible conformational change to the 135S cell entry intermediate. This transition involves shifts of the capsid protein beta barrels, accompanied by the externalization of VP4 and the N terminus of VP1. Both polypeptides associate with membranes and are postulated to facilitate entry by forming a translocation pore for the viral RNA. We have calculated cryo-electron microscopic reconstructions of 135S particles that permit accurate placement of the beta barrels, loops, and terminal extensions of the capsid proteins. The reconstructions and resulting models indicate that each N terminus of VP1 exits the capsid though an opening in the interface between VP1 and VP3 at the base of the canyon that surrounds the fivefold axis. Comparison with reconstructions of 135S particles in which the first 31 residues of VP1 were proteolytically removed revealed that the externalized N terminus is located near the tips of propeller-like features surrounding the threefold axes rather than at the fivefold axes, as had been proposed in previous models. These observations have forced a reexamination of current models for the role of the 135S particle in transmembrane pore formation and suggest testable alternatives.
About this Structure
1XYR is a Protein complex structure of sequences from Human poliovirus 1. Full crystallographic information is available from OCA.
Reference
The structure of the poliovirus 135S cell entry intermediate at 10-angstrom resolution reveals the location of an externalized polypeptide that binds to membranes., Bubeck D, Filman DJ, Cheng N, Steven AC, Hogle JM, Belnap DM, J Virol. 2005 Jun;79(12):7745-55. PMID:15919927
Page seeded by OCA on Thu Feb 21 16:00:02 2008
