View source for 8v5o


==Tetramer core subcomplex (conformation 3) of Xenopus laevis DNA polymerase alpha-primase==
<StructureSection load='8v5o' size='340' side='right'caption='[[8v5o]], [[Resolution|resolution]] 8.99&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8v5o]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Xenopus_laevis Xenopus laevis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8V5O OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8V5O FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 8.99&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><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=8v5o FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8v5o OCA], [https://pdbe.org/8v5o PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8v5o RCSB], [https://www.ebi.ac.uk/pdbsum/8v5o PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8v5o ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/DPOLA_XENLA DPOLA_XENLA] Plays an essential role in the initiation of DNA replication. During the S phase of the cell cycle, the DNA polymerase alpha complex (composed of a catalytic subunit POLA1/p180, a regulatory subunit POLA2/p70 and two primase subunits PRIM1/p49 and PRIM2/p58) is recruited to DNA at the replicative forks via direct interactions with MCM10 and WDHD1. The primase subunit of the polymerase alpha complex initiates DNA synthesis by oligomerising short RNA primers on both leading and lagging strands. These primers are initially extended by the polymerase alpha catalytic subunit and subsequently transferred to polymerase delta and polymerase epsilon for processive synthesis on the lagging and leading strand, respectively. The reason this transfer occurs is because the polymerase alpha has limited processivity and lacks intrinsic 3' exonuclease activity for proofreading error, and therefore is not well suited for replicating long complexes (By similarity).
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</StructureSection>
[[Category: Large Structures]]
[[Category: Xenopus laevis]]
[[Category: Chazin WJ]]
[[Category: Eichman BF]]
[[Category: Mullins EA]]