1za7: Difference between revisions

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[[Image:1za7.gif|left|200px]]<br /><applet load="1za7" size="~~450~~" color="white" frame="true" align="right" spinBox="true"

[[Image:1za7.gif|left|200px]]<br /><applet load="1za7" size="350" color="white" frame="true" align="right" spinBox="true"

caption="1za7, resolution 2.70Å" />

'''The crystal structure of salt stable cowpea cholorotic mottle virus at 2.7 angstroms resolution.'''<br />

==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.

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 [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://~~ispc~~.weizmann.ac.il/oca-bin/ocashort?id=1ZA7 OCA].

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==

Line 14:

[[Category: Single protein]]

[[Category: Bothner, B.]]

[[Category: Johnson, J.E.]]

[[Category: Johnson, J E.]]

[[Category: Qu, C.]]

[[Category: Speir, J.A.]]

[[Category: Speir, J A.]]

[[Category: Willits, D.A.]]

[[Category: Willits, D A.]]

[[Category: Young, M.J.]]

[[Category: Young, M J.]]

[[Category: beta barrel]]

[[Category: beta hexamer]]

Line 29:

[[Category: stablizing mutation]]

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@@ Line 1: / Line 1: @@
-[[Image:1za7.gif|left|200px]]<br /><applet load="1za7" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1za7.gif|left|200px]]<br /><applet load="1za7" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1za7, resolution 2.70&Aring;" />
 '''The crystal structure of salt stable cowpea cholorotic mottle virus at 2.7 angstroms resolution.'''<br />
 ==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.
+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==
-ZA7 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://ispc.weizmann.ac.il/oca-bin/ocashort?id=1ZA7 OCA].
+ZA7 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==
@@ Line 14: / Line 14: @@
 [[Category: Single protein]]
 [[Category: Bothner, B.]]
-[[Category: Johnson, J.E.]]
+[[Category: Johnson, J E.]]
 [[Category: Qu, C.]]
-[[Category: Speir, J.A.]]
+[[Category: Speir, J A.]]
-[[Category: Willits, D.A.]]
+[[Category: Willits, D A.]]
-[[Category: Young, M.J.]]
+[[Category: Young, M J.]]
 [[Category: beta barrel]]
 [[Category: beta hexamer]]
@@ Line 29: / Line 29: @@
 [[Category: stablizing mutation]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 07:20:18 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:13:37 2008''