User:Udayan Shevade/Sandbox1
From Proteopedia
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Revision as of 23:03, 12 November 2011
Contents |
SV40 Large T Antigen
Introduction
The SV40 large tumor antigen is a multifunctional regulatory protein encoded by Simian Virus 40. It is classified under the AAA+ family of helicases [1]. Noteworthy for its versatility, the protein is responsible for initiation of viral DNA replication, regulation of viral transcription and transformation of the host cell to promote viral infectivity. Large T-antigen is an early gene product of SV40 and is produced via differential mRNA splicing.
Structure
T antigen is a 708-amino acid protein with three major domains: an N-terminal J domain, a central origin-binding domain, and a C-terminal helicase domain [2]. The activities of each are covered briefly below.
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| 1svm, resolution 1.94Å () | |||||||||
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| Ligands: | , , | ||||||||
| Related: | 1svl, 1svo | ||||||||
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| Resources: | FirstGlance, OCA, RCSB, PDBsum | ||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||
Helicase
The helicase monomer consists of a AAA+ domain. As with the origin-binding domain, these monomers also hexamerize. However the complex does not form a spiral, but a flat ring. Each monomer binds and hydrolyzes an ATP in the presence of magnesium ion and drives an overall conformational change in the hexamer.
References
- ↑ 1.0 1.1 Luo X, Sanford DG, Bullock PA, Bachovchin WW. Solution structure of the origin DNA-binding domain of SV40 T-antigen. Nat Struct Biol. 1996 Dec;3(12):1034-9. PMID:8946857
- ↑ Gai D, Zhao R, Li D, Finkielstein CV, Chen XS. Mechanisms of conformational change for a replicative hexameric helicase of SV40 large tumor antigen. Cell. 2004 Oct 1;119(1):47-60. PMID:15454080 doi:10.1016/j.cell.2004.09.017
- ↑ Falchuk KH, Czupryn M. Isolation of metallothioneins under metal-free conditions. Methods Enzymol. 1991;205:47-53. PMID:1779811
