View source for 5ikn


==Crystal Structure of the T7 Replisome in the Absence of DNA==
<StructureSection load='5ikn' size='340' side='right'caption='[[5ikn]], [[Resolution|resolution]] 4.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5ikn]] is a 13 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_O157:H7 Escherichia coli O157:H7] and [https://en.wikipedia.org/wiki/Escherichia_phage_T7 Escherichia phage T7]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5IKN OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5IKN FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 4.802&#8491;</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=5ikn FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5ikn OCA], [https://pdbe.org/5ikn PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5ikn RCSB], [https://www.ebi.ac.uk/pdbsum/5ikn PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5ikn ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/DPOL_BPT7 DPOL_BPT7] Replicates viral genomic DNA. Non-processive DNA polymerase that achieves processivity by binding to host thioredoxin (TrxA). This interaction increases the rate of dNTP incorporation to yield a processivity of approximately 800 nucleotides (nt) per binding event. Interacts with DNA helicase gp4 to coordinate nucleotide polymerization with unwinding of the DNA. The leading strand is synthesized continuously while synthesis of the lagging strand requires the synthesis of oligoribonucleotides by the primase domain of gp4.<ref>PMID:9218486</ref> <ref>PMID:21606333</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The physical organization of DNA enzymes at a replication fork enables efficient copying of two antiparallel DNA strands, yet dynamic protein interactions within the replication complex complicate replisome structural studies. We employed a combination of crystallographic, native mass spectrometry and small-angle X-ray scattering experiments to capture alternative structures of a model replication system encoded by bacteriophage T7. Two molecules of DNA polymerase bind the ring-shaped primase-helicase in a conserved orientation and provide structural insight into how the acidic C-terminal tail of the primase-helicase contacts the DNA polymerase to facilitate loading of the polymerase onto DNA. A third DNA polymerase binds the ring in an offset manner that may enable polymerase exchange during replication. Alternative polymerase binding modes are also detected by small-angle X-ray scattering with DNA substrates present. Our collective results unveil complex motions within T7 replisome higher-order structures that are underpinned by multivalent protein-protein interactions with functional implications.

Hybrid Methods Reveal Multiple Flexibly Linked DNA Polymerases within the Bacteriophage T7 Replisome.,Wallen JR, Zhang H, Weis C, Cui W, Foster BM, Ho CM, Hammel M, Tainer JA, Gross ML, Ellenberger T Structure. 2017 Jan 3;25(1):157-166. doi: 10.1016/j.str.2016.11.019. PMID:28052235<ref>PMID:28052235</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5ikn" style="background-color:#fffaf0;"></div>

==See Also==
*[[DNA polymerase 3D structures|DNA polymerase 3D structures]]
*[[RNA polymerase 3D structures|RNA polymerase 3D structures]]
*[[Thioredoxin 3D structures|Thioredoxin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli O157:H7]]
[[Category: Escherichia phage T7]]
[[Category: Large Structures]]
[[Category: Ellenberger T]]
[[Category: Wallen JR]]