View source for 4xxo


==Crystal Structure of Human APOBEC3A==
<StructureSection load='4xxo' size='340' side='right'caption='[[4xxo]], [[Resolution|resolution]] 2.84&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4xxo]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4XXO OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4XXO 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]] 2.843&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</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=4xxo FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4xxo OCA], [https://pdbe.org/4xxo PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4xxo RCSB], [https://www.ebi.ac.uk/pdbsum/4xxo PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4xxo ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ABC3A_HUMAN ABC3A_HUMAN] DNA deaminase (cytidine deaminase) with restriction activity against viruses, foreign DNA and mobility of retrotransposons. Exhibits antiviral activity against adeno-associated virus (AAV) and human T-cell leukemia virus type 1 (HTLV-1) and may inhibit the mobility of LTR and non-LTR retrotransposons. Selectively targets single-stranded DNA and can deaminate both methylcytosine and cytosine in foreign DNA. Can induce somatic hypermutation in the nuclear and mitochondrial DNA. May also play a role in the epigenetic regulation of gene expression through the process of active DNA demethylation.<ref>PMID:10469298</ref> <ref>PMID:12859895</ref> <ref>PMID:16527742</ref> <ref>PMID:19461882</ref> <ref>PMID:20615867</ref> <ref>PMID:20062055</ref> <ref>PMID:21496894</ref> <ref>PMID:21460793</ref> <ref>PMID:21123384</ref> <ref>PMID:21368204</ref> <ref>PMID:22896697</ref> <ref>PMID:22457529</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Deaminase activity mediated by the human APOBEC3 family of proteins contributes to genomic instability and cancer. APOBEC3A is by far the most active in this family and can cause rapid cell death when overexpressed, but in general how the activity of APOBEC3s is regulated on a molecular level is unclear. In this study, the biochemical and structural basis of APOBEC3A substrate binding and specificity is elucidated. We find that specific binding of single-stranded DNA is regulated by the cooperative dimerization of APOBEC3A. The crystal structure elucidates this homodimer as a symmetric domain swap of the N-terminal residues. This dimer interface provides insights into how cooperative protein-protein interactions may affect function in the APOBEC3 enzymes and provides a potential scaffold for strategies aimed at reducing their mutation load.

The ssDNA Mutator APOBEC3A Is Regulated by Cooperative Dimerization.,Bohn MF, Shandilya SM, Silvas TV, Nalivaika EA, Kouno T, Kelch BA, Ryder SP, Kurt-Yilmaz N, Somasundaran M, Schiffer CA Structure. 2015 May 5;23(5):903-11. doi: 10.1016/j.str.2015.03.016. Epub 2015 Apr, 23. PMID:25914058<ref>PMID:25914058</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4xxo" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Bohn MF]]
[[Category: Schiffer CA]]
[[Category: Shandilya SMD]]