View source for 5ftb


==Crystal structure of Pif1 helicase from Bacteroides in complex with AMPPNP==
<StructureSection load='5ftb' size='340' side='right'caption='[[5ftb]], [[Resolution|resolution]] 1.38&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5ftb]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Bacteroides_sp._3_1_23 Bacteroides sp. 3_1_23]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5FTB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5FTB 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]] 1.38&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ANP:PHOSPHOAMINOPHOSPHONIC+ACID-ADENYLATE+ESTER'>ANP</scene>, <scene name='pdbligand=K:POTASSIUM+ION'>K</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</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=5ftb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5ftb OCA], [https://pdbe.org/5ftb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5ftb RCSB], [https://www.ebi.ac.uk/pdbsum/5ftb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5ftb ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/D7K0H3_9BACE D7K0H3_9BACE] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Pif1 helicases are ubiquitous members of the SF1B family and are essential for maintaining genome stability. It was speculated that Pif1-specific motifs may fold in specific structures, conferring distinct activities upon it. Here, we report the crystal structures of the Pif1 helicase from Bacteroides spp with and without adenosine triphosphate (ATP) analog/ssDNA. BsPif1 shares structural similarities with RecD2 and Dda helicases but has specific features in the 1B and 2B domains. The highly conserved Pif1 family specific sequence motif interacts with and constraints a putative pin-loop in domain 1B in a precise conformation. More importantly, we found that the 2B domain which contains a specific extended hairpin undergoes a significant rotation and/or movement upon ATP and DNA binding, which is absolutely required for DNA unwinding. We therefore propose a mechanism for DNA unwinding in which the 2B domain plays a predominant role. The fact that the conformational change regulates Pif1 activity may provide insight into the puzzling observation that Pif1 becomes highly processive during break-induced replication in association with Poldelta, while the isolated Pif1 has low processivity.

Crystal structures of the BsPif1 helicase reveal that a major movement of the 2B SH3 domain is required for DNA unwinding.,Chen WF, Dai YX, Duan XL, Liu NN, Shi W, Li N, Li M, Dou SX, Dong YH, Rety S, Xi XG Nucleic Acids Res. 2016 Jan 24. pii: gkw033. PMID:26809678<ref>PMID:26809678</ref>

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

==See Also==
*[[Helicase 3D structures|Helicase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Bacteroides sp. 3_1_23]]
[[Category: Large Structures]]
[[Category: Chen W-F]]
[[Category: Dai Y-X]]
[[Category: Dong Y-H]]
[[Category: Dou S-X]]
[[Category: Duan X-L]]
[[Category: Li M]]
[[Category: Li N]]
[[Category: Liu N-N]]
[[Category: Rety S]]
[[Category: Shi W]]
[[Category: Xi X-G]]