1svm

Co-crystal structure of SV40 large T antigen helicase domain and ATP

File:1svm.gif

spinqualitylabelsall models PDB ID 1svm Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image
1svm, resolution 1.94Å ()
Ligands:	, ,
Related:	1svl, 1svo
Structural annotation: Resources: CATH : 1Svma03, 1Svma01, 1Svmb01, 1Svmb03, 1Svmc01, 1Svmc03, 1Svmd01, 1Svmd03, 1Svme01, 1Svme03, 1Svmf01, 1Svmf03 InterPro : Ipr014015, Ipr010932, Ipr003133, Ipr001623 Pfam : PF06431 UniProt : P03070
Functional annotation: Cellular component: nucleus Biological process: DNA replication Molecular function: ATP binding heat shock protein binding metal ion binding nucleotide binding zinc ion binding DNA binding DNA replication origin binding protein binding
Evolutionary conservation: Toggle Conservation Colors: Rows = identical sequences: Further Information: Caveats, Explanation, Complete Results at ConSurfDB
Resources:	FirstGlance, OCA, RCSB, PDBsum
Coordinates:	save as pdb, mmCIF, xml

OverviewOverview

The large tumor antigen (LTag) of simian virus 40, an AAA(+) protein, is a hexameric helicase essential for viral DNA replication in eukaryotic cells. LTag functions as an efficient molecular machine powered by ATP binding and hydrolysis for origin DNA melting and replication fork unwinding. To understand how ATP binding and hydrolysis are coupled to conformational changes, we have determined high-resolution structures ( approximately 1.9 A) of LTag hexamers in distinct nucleotide binding states. The structural differences of LTag in various nucleotide states detail the molecular mechanisms of conformational changes triggered by ATP binding/hydrolysis and reveal a potential mechanism of concerted nucleotide binding and hydrolysis. During these conformational changes, the angles and orientations between domains of a monomer alter, creating an "iris"-like motion in the hexamer. Additionally, six unique beta hairpins on the channel surface move longitudinally along the central channel, possibly serving as a motor for pulling DNA into the LTag double hexamer for unwinding.

About this StructureAbout this Structure

1SVM is a Single protein structure of sequence from Simian virus 40. The following page contains interesting information on the relation of 1SVM with [AAA+ Proteases]. Full crystallographic information is available from OCA.

ReferenceReference

Mechanisms of conformational change for a replicative hexameric helicase of SV40 large tumor antigen., Gai D, Zhao R, Li D, Finkielstein CV, Chen XS, Cell. 2004 Oct 1;119(1):47-60. PMID:15454080 Page seeded by OCA on Sat May 3 09:11:18 2008