View source for 1za7

[[Image:1za7.gif|left|200px]]

 {{Structure
|PDB= 1za7 |SIZE=350|CAPTION= <scene name='initialview01'>1za7</scene>, resolution 2.70&Aring;
|SITE= 
|LIGAND= 
|ACTIVITY= 
|GENE= RNA4 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=12303 Cowpea chlorotic mottle virus])
|DOMAIN=
|RELATEDENTRY=[[1cwp|1cwp]]
|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1za7 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1za7 OCA], [http://www.ebi.ac.uk/pdbsum/1za7 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1za7 RCSB]</span>
}}

'''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 [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==
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:[http://www.ncbi.nlm.nih.gov/pubmed/16537626 16537626]
[[Category: Cowpea chlorotic mottle virus]]
[[Category: Single protein]]
[[Category: Bothner, B.]]
[[Category: Johnson, J E.]]
[[Category: Qu, C.]]
[[Category: Speir, J A.]]
[[Category: Willits, D A.]]
[[Category: Young, M J.]]
[[Category: beta barrel]]
[[Category: beta hexamer]]
[[Category: bromovirus]]
[[Category: icosahedral particle]]
[[Category: icosahedral virus]]
[[Category: mutant virus capsid structure]]
[[Category: point mutation]]
[[Category: stable mutant]]
[[Category: stablizing mutation]]

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