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< | ==K263A mutant of PolX from Thermus thermophilus HB8 complexed with Ca-dGTP== | ||
<StructureSection load='3b0x' size='340' side='right'caption='[[3b0x]], [[Resolution|resolution]] 1.36Å' scene=''> | |||
== Structural highlights == | |||
or the | <table><tr><td colspan='2'>[[3b0x]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Thermus_thermophilus_HB8 Thermus thermophilus HB8]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3B0X OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3B0X FirstGlance]. <br> | ||
or | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.36Å</td></tr> | ||
-- | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=DGT:2-DEOXYGUANOSINE-5-TRIPHOSPHATE'>DGT</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr> | ||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=3b0x FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3b0x OCA], [https://pdbe.org/3b0x PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3b0x RCSB], [https://www.ebi.ac.uk/pdbsum/3b0x PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3b0x ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/Q5SJ64_THET8 Q5SJ64_THET8] | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
DNA with single-nucleotide (1-nt) gaps can arise during various DNA processing events. These lesions are repaired by X-family DNA polymerases (PolXs) with high gap-filling activity. Some PolXs can bind productively to dNTPs in the absence of DNA and fill these 1-nt gaps. Although PolXs have a crucial role in efficient gap filling, currently, little is known of the kinetic and structural details of their productive dNTP binding. Here, we show that Thermus thermophilus HB8 PolX (ttPolX) had strong binding affinity for Mg(2+)-dNTPs in the absence of DNA and that it follows a Theorell-Chance (hit-and-run) mechanism with nucleotide binding first. Comparison of the intermediate crystal structures of ttPolX in a binary complex with dGTP and in a ternary complex with 1-nt gapped DNA and Mg(2+)-ddGTP revealed that the conformation of the incoming nucleotide depended on whether or not DNA was present. Furthermore, the Lys263 residue located between two guanosine conformations was essential to the strong binding affinity of the enzyme. The ability to bind to either syn-dNTP or anti-dNTP and the involvement of a Theorell-Chance mechanism are key aspects of the strong nucleotide-binding and efficient gap-filling activities of ttPolX. | |||
The structural basis of the kinetic mechanism of a gap-filling X-family DNA polymerase that binds Mg(2+)-dNTP before binding to DNA.,Nakane S, Ishikawa H, Nakagawa N, Kuramitsu S, Masui R J Mol Biol. 2012 Mar 30;417(3):179-96. Epub 2012 Jan 27. PMID:22306405<ref>PMID:22306405</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 3b0x" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[DNA polymerase 3D structures|DNA polymerase 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
== | [[Category: Large Structures]] | ||
[[ | [[Category: Thermus thermophilus HB8]] | ||
[[Category: Kuramitsu S]] | |||
== | [[Category: Masui R]] | ||
< | [[Category: Nakagawa N]] | ||
[[Category: | [[Category: Nakane S]] | ||
[[Category: Thermus thermophilus]] | |||
[[Category: Kuramitsu | |||
[[Category: Masui | |||
[[Category: Nakagawa | |||
[[Category: Nakane | |||
Latest revision as of 11:51, 11 October 2023
K263A mutant of PolX from Thermus thermophilus HB8 complexed with Ca-dGTPK263A mutant of PolX from Thermus thermophilus HB8 complexed with Ca-dGTP
Structural highlights
FunctionPublication Abstract from PubMedDNA with single-nucleotide (1-nt) gaps can arise during various DNA processing events. These lesions are repaired by X-family DNA polymerases (PolXs) with high gap-filling activity. Some PolXs can bind productively to dNTPs in the absence of DNA and fill these 1-nt gaps. Although PolXs have a crucial role in efficient gap filling, currently, little is known of the kinetic and structural details of their productive dNTP binding. Here, we show that Thermus thermophilus HB8 PolX (ttPolX) had strong binding affinity for Mg(2+)-dNTPs in the absence of DNA and that it follows a Theorell-Chance (hit-and-run) mechanism with nucleotide binding first. Comparison of the intermediate crystal structures of ttPolX in a binary complex with dGTP and in a ternary complex with 1-nt gapped DNA and Mg(2+)-ddGTP revealed that the conformation of the incoming nucleotide depended on whether or not DNA was present. Furthermore, the Lys263 residue located between two guanosine conformations was essential to the strong binding affinity of the enzyme. The ability to bind to either syn-dNTP or anti-dNTP and the involvement of a Theorell-Chance mechanism are key aspects of the strong nucleotide-binding and efficient gap-filling activities of ttPolX. The structural basis of the kinetic mechanism of a gap-filling X-family DNA polymerase that binds Mg(2+)-dNTP before binding to DNA.,Nakane S, Ishikawa H, Nakagawa N, Kuramitsu S, Masui R J Mol Biol. 2012 Mar 30;417(3):179-96. Epub 2012 Jan 27. PMID:22306405[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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