2im2: Difference between revisions
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[[Image: | ==Crystal structure of poliovirus polymerase complexed with UTP and Mg2+== | ||
<StructureSection load='2im2' size='340' side='right' caption='[[2im2]], [[Resolution|resolution]] 2.35Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[2im2]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Human_poliovirus_1 Human poliovirus 1]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2IM2 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2IM2 FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ACY:ACETIC+ACID'>ACY</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=UTP:URIDINE+5-TRIPHOSPHATE'>UTP</scene><br> | |||
<tr><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=CAS:S-(DIMETHYLARSENIC)CYSTEINE'>CAS</scene></td></tr> | |||
<tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1ra7|1ra7]], [[1ra6|1ra6]], [[2ily|2ily]], [[2ilz|2ilz]], [[2im0|2im0]], [[2im1|2im1]], [[2im3|2im3]]</td></tr> | |||
<tr><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">3D ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=12080 Human poliovirus 1])</td></tr> | |||
<tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/RNA-directed_RNA_polymerase RNA-directed RNA polymerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.48 2.7.7.48] </span></td></tr> | |||
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2im2 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2im2 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2im2 RCSB], [http://www.ebi.ac.uk/pdbsum/2im2 PDBsum]</span></td></tr> | |||
<table> | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/im/2im2_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The viral RNA-dependent RNA polymerases show a conserved structure where the fingers domain interacts with the top of the thumb domain to create a tunnel through which nucleotide triphosphates reach the active site. We have solved the crystal structures of poliovirus polymerase (3D(pol)) in complex with all four NTPs, showing that they all bind in a common pre-insertion site where the phosphate groups are not yet positioned over the active site. The NTPs interact with both the fingers and palm domains, forming bridging interactions that explain the increased thermal stability of 3D(pol) in the presence of NTPs. We have also examined the importance of the fingers-thumb domain interaction for the function and structural stability of 3D(pol). Results from thermal denaturation experiments using circular dichroism and 2-anilino-6-napthaline-sulfonate (ANS) fluorescence show that 3D(pol) has a melting temperature of only approximately 40 degrees C. NTP binding stabilizes the protein and increases the melting by 5-6 degrees C while mutations in the fingers-thumb domain interface destabilize the protein and reduce the melting point by as much as 6 degrees C. In particular, the burial of Phe30 and Phe34 from the tip of the index finger into a pocket at the top of the thumb and the presence of Trp403 on the thumb domain are key interactions required to maintain the structural integrity of the polymerase. The data suggest the fingers domain has significant conformational flexibility and exists in a highly dynamic molten globule state at physiological temperature. The role of the enclosed active site motif as a structural scaffold for constraining the fingers domain and accommodating conformational changes in 3D(pol) and other viral polymerases during the catalytic cycle is discussed. | |||
Stabilization of poliovirus polymerase by NTP binding and fingers-thumb interactions.,Thompson AA, Albertini RA, Peersen OB J Mol Biol. 2007 Mar 9;366(5):1459-74. Epub 2006 Dec 1. PMID:17223130<ref>PMID:17223130</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | |||
*[[RNA polymerase|RNA polymerase]] | |||
== | == References == | ||
[[ | <references/> | ||
__TOC__ | |||
== | </StructureSection> | ||
< | |||
[[Category: Human poliovirus 1]] | [[Category: Human poliovirus 1]] | ||
[[Category: RNA-directed RNA polymerase]] | [[Category: RNA-directed RNA polymerase]] | ||
Revision as of 12:24, 30 September 2014
Crystal structure of poliovirus polymerase complexed with UTP and Mg2+Crystal structure of poliovirus polymerase complexed with UTP and Mg2+
Structural highlights
Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe viral RNA-dependent RNA polymerases show a conserved structure where the fingers domain interacts with the top of the thumb domain to create a tunnel through which nucleotide triphosphates reach the active site. We have solved the crystal structures of poliovirus polymerase (3D(pol)) in complex with all four NTPs, showing that they all bind in a common pre-insertion site where the phosphate groups are not yet positioned over the active site. The NTPs interact with both the fingers and palm domains, forming bridging interactions that explain the increased thermal stability of 3D(pol) in the presence of NTPs. We have also examined the importance of the fingers-thumb domain interaction for the function and structural stability of 3D(pol). Results from thermal denaturation experiments using circular dichroism and 2-anilino-6-napthaline-sulfonate (ANS) fluorescence show that 3D(pol) has a melting temperature of only approximately 40 degrees C. NTP binding stabilizes the protein and increases the melting by 5-6 degrees C while mutations in the fingers-thumb domain interface destabilize the protein and reduce the melting point by as much as 6 degrees C. In particular, the burial of Phe30 and Phe34 from the tip of the index finger into a pocket at the top of the thumb and the presence of Trp403 on the thumb domain are key interactions required to maintain the structural integrity of the polymerase. The data suggest the fingers domain has significant conformational flexibility and exists in a highly dynamic molten globule state at physiological temperature. The role of the enclosed active site motif as a structural scaffold for constraining the fingers domain and accommodating conformational changes in 3D(pol) and other viral polymerases during the catalytic cycle is discussed. Stabilization of poliovirus polymerase by NTP binding and fingers-thumb interactions.,Thompson AA, Albertini RA, Peersen OB J Mol Biol. 2007 Mar 9;366(5):1459-74. Epub 2006 Dec 1. PMID:17223130[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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