Sandbox TMV
From Proteopedia
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<StructureSection load="2tmv" size="400" color="" frame="true" spin="on" Scene='Tobacco_Mosaic_Virus/2tmv_lockwasher_ring/1' align="right" caption="TMV coat protein [[2tmv]]" > | <StructureSection load="2tmv" size="400" color="" frame="true" spin="on" Scene='Tobacco_Mosaic_Virus/2tmv_lockwasher_ring/1' align="right" caption="TMV coat protein [[2tmv]]" > | ||
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| - | ===Protein-nucleic acid interactions in the Tobacco virus.([[2tmv]])=== | ||
==Tobacco Mosaic Virus== | ==Tobacco Mosaic Virus== | ||
| - | Tobacco Mosaic Virus (TMV) is composed of 2130 identical coat protein subunits following the | + | Tobacco Mosaic Virus (TMV)is a positive-sense single stranded RNA virus that infects plants, especially tobacco and other members of the family Solanaceae. The infection causes characteristic patterns, such as "mosaic"-like mottling and discoloration on the leaves (hence the name). TMV was the first virus to ever be discovered. It is composed of 2130 identical coat protein subunits following the |
right-handed helix of an accompanying RNA strand to produce a 300 nm hollow cylinder with an | right-handed helix of an accompanying RNA strand to produce a 300 nm hollow cylinder with an | ||
| - | outer diameter of 18 nm and a 4 nm wide central channel. | + | outer diameter of 18 nm and a 4 nm wide central channel. This here is a protein-nucleic acid interactions in the virus. |
==Caspar Carboxylates== | ==Caspar Carboxylates== | ||
| - | Two clusters of acidic amino acids are thought to be important for the disassembly of the <scene name='2tmv/2tmv_lockwasher_ring/1'>helical structure of TMV</scene>. When the virus enters cells, the higher pH and lower calcium levels increase the repulsion of neighboring carboxylates, destabilizing the capsid. This concept was originally proposed by Caspar and subsequently examined by site-directed mutagenesis <ref>Caspar carboxylates: the structural basis of tobamovirus assembly. Wang H, Planchart A, Stubbs G. Biophys. J. 1998, 74, 633-638.</ref>. Several carboxylates were identified including <scene name='2tmv/2tmv_carbox1/2'>Glu50 and ASP77</scene>, which contact each other in the helical stack (look closely at the <scene name='2tmv/2tmv_carbox1_closeup/1'>two subunits that overlap</scene> in this lockwasher complex), and a cluster of four acidic amino acids, <scene name='2tmv/2tmv_carbox2/2'>GLU95, GLU97, GLU106 and GLU109</scene>, near the center of the ring. | + | Two clusters of acidic amino acids are thought to be important for the disassembly of the <scene name='2tmv/2tmv_lockwasher_ring/1'>helical structure of TMV</scene>. When the virus enters cells, the higher pH and lower calcium levels increase the repulsion of neighboring carboxylates, destabilizing the capsid. This concept was originally proposed by Caspar and subsequently examined by site-directed mutagenesis <ref>Caspar carboxylates: the structural basis of tobamovirus assembly. Wang H, Planchart A, Stubbs G. Biophys. J. 1998, 74, 633-638.</ref>. Several carboxylates were identified including <scene name='2tmv/2tmv_carbox1/2'>Glu50 and ASP77</scene>, which contact each other in the helical stack by hydrogen bonds(look closely at the <scene name='2tmv/2tmv_carbox1_closeup/1'>two subunits that overlap</scene> in this lockwasher complex), and a cluster of four acidic amino acids, <scene name='2tmv/2tmv_carbox2/2'>GLU95, GLU97, GLU106 and GLU109</scene>, near the center of the ring. |
<blockquote> | <blockquote> | ||
Revision as of 15:57, 15 October 2013
Tobacco Mosaic Virus
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3D structures of tobacco mosaic virus
Updated on 15-October-2013
2om3, 2xea – TMV coat protein + RNA - CryoEM
2tmv – TMV coat protein + RNA - fiber
References
Primary Reference
Visualization of protein-nucleic acid interactions in a virus. Refined structure of intact tobacco mosaic virus at 2.9 A resolution by X-ray fiber diffraction., Namba K, Pattanayek R, Stubbs G, J Mol Biol. 1989 Jul 20;208(2):307-25. PMID:2769760
Additional References
- ↑ Caspar carboxylates: the structural basis of tobamovirus assembly. Wang H, Planchart A, Stubbs G. Biophys. J. 1998, 74, 633-638.
Created with the participation of Jaime Prilusky, Eran Hodis, David S. Goodsell.
