1za7
From Proteopedia
(New page: 200px<br /><applet load="1za7" size="450" color="white" frame="true" align="right" spinBox="true" caption="1za7, resolution 2.70Å" /> '''The crystal structur...) |
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| - | [[Image:1za7.gif|left|200px]]<br /><applet load="1za7" size=" | + | [[Image:1za7.gif|left|200px]]<br /><applet load="1za7" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1za7, resolution 2.70Å" /> | caption="1za7, resolution 2.70Å" /> | ||
'''The crystal structure of salt stable cowpea cholorotic mottle virus at 2.7 angstroms resolution.'''<br /> | '''The crystal structure of salt stable cowpea cholorotic mottle virus at 2.7 angstroms resolution.'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Structural transitions in viral capsids play a critical role in the virus | + | Structural transitions in viral capsids play a critical role in the virus life cycle, including assembly, disassembly, and release of the packaged nucleic acid. Cowpea chlorotic mottle virus (CCMV) undergoes a well-studied reversible structural expansion in vitro in which the capsid expands by 10%. The swollen form of the particle can be completely disassembled by increasing the salt concentration to 1 M. Remarkably, a single-residue mutant of the CCMV N-terminal arm, K42R, is not susceptible to dissociation in high salt (salt-stable CCMV [SS-CCMV]) and retains 70% of wild-type infectivity. We present the combined structural and biophysical basis for the chemical stability and viability of the SS-CCMV particles. A 2.7-A resolution crystal structure of the SS-CCMV capsid shows an addition of 660 new intersubunit interactions per particle at the center of the 20 hexameric capsomeres, which are a direct result of the K42R mutation. Protease-based mapping experiments of intact particles demonstrate that both the swollen and closed forms of the wild-type and SS-CCMV particles have highly dynamic N-terminal regions, yet the SS-CCMV particles are more resistant to degradation. Thus, the increase in SS-CCMV particle stability is a result of concentrated tethering of subunits at a local symmetry interface (i.e., quasi-sixfold axes) that does not interfere with the function of other key symmetry interfaces (i.e., fivefold, twofold, quasi-threefold axes). The result is a particle that is still dynamic but insensitive to high salt due to a new series of bonds that are resistant to high ionic strength and preserve the overall particle structure. |
==About this Structure== | ==About this Structure== | ||
| - | 1ZA7 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Cowpea_chlorotic_mottle_virus Cowpea chlorotic mottle virus]. Full crystallographic information is available from [http:// | + | 1ZA7 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Cowpea_chlorotic_mottle_virus Cowpea chlorotic mottle virus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ZA7 OCA]. |
==Reference== | ==Reference== | ||
| Line 14: | Line 14: | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Bothner, B.]] | [[Category: Bothner, B.]] | ||
| - | [[Category: Johnson, J | + | [[Category: Johnson, J E.]] |
[[Category: Qu, C.]] | [[Category: Qu, C.]] | ||
| - | [[Category: Speir, J | + | [[Category: Speir, J A.]] |
| - | [[Category: Willits, D | + | [[Category: Willits, D A.]] |
| - | [[Category: Young, M | + | [[Category: Young, M J.]] |
[[Category: beta barrel]] | [[Category: beta barrel]] | ||
[[Category: beta hexamer]] | [[Category: beta hexamer]] | ||
| Line 29: | Line 29: | ||
[[Category: stablizing mutation]] | [[Category: stablizing mutation]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:13:37 2008'' |
Revision as of 14:13, 21 February 2008
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The crystal structure of salt stable cowpea cholorotic mottle virus at 2.7 angstroms resolution.
Overview
Structural transitions in viral capsids play a critical role in the virus life cycle, including assembly, disassembly, and release of the packaged nucleic acid. Cowpea chlorotic mottle virus (CCMV) undergoes a well-studied reversible structural expansion in vitro in which the capsid expands by 10%. The swollen form of the particle can be completely disassembled by increasing the salt concentration to 1 M. Remarkably, a single-residue mutant of the CCMV N-terminal arm, K42R, is not susceptible to dissociation in high salt (salt-stable CCMV [SS-CCMV]) and retains 70% of wild-type infectivity. We present the combined structural and biophysical basis for the chemical stability and viability of the SS-CCMV particles. A 2.7-A resolution crystal structure of the SS-CCMV capsid shows an addition of 660 new intersubunit interactions per particle at the center of the 20 hexameric capsomeres, which are a direct result of the K42R mutation. Protease-based mapping experiments of intact particles demonstrate that both the swollen and closed forms of the wild-type and SS-CCMV particles have highly dynamic N-terminal regions, yet the SS-CCMV particles are more resistant to degradation. Thus, the increase in SS-CCMV particle stability is a result of concentrated tethering of subunits at a local symmetry interface (i.e., quasi-sixfold axes) that does not interfere with the function of other key symmetry interfaces (i.e., fivefold, twofold, quasi-threefold axes). The result is a particle that is still dynamic but insensitive to high salt due to a new series of bonds that are resistant to high ionic strength and preserve the overall particle structure.
About this Structure
1ZA7 is a Single protein structure of sequence from Cowpea chlorotic mottle virus. Full crystallographic information is available from OCA.
Reference
Enhanced local symmetry interactions globally stabilize a mutant virus capsid that maintains infectivity and capsid dynamics., Speir JA, Bothner B, Qu C, Willits DA, Young MJ, Johnson JE, J Virol. 2006 Apr;80(7):3582-91. PMID:16537626
Page seeded by OCA on Thu Feb 21 16:13:37 2008
Categories: Cowpea chlorotic mottle virus | Single protein | Bothner, B. | Johnson, J E. | Qu, C. | Speir, J A. | Willits, D A. | Young, M J. | Beta barrel | Beta hexamer | Bromovirus | Icosahedral particle | Icosahedral virus | Mutant virus capsid structure | Point mutation | Stable mutant | Stablizing mutation
