View source for 5hx5


==APOBEC3F Catalytic Domain Crystal Structure==
<StructureSection load='5hx5' size='340' side='right'caption='[[5hx5]], [[Resolution|resolution]] 2.33&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5hx5]] 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=5HX5 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5HX5 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]] 2.33&#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=5hx5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5hx5 OCA], [https://pdbe.org/5hx5 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5hx5 RCSB], [https://www.ebi.ac.uk/pdbsum/5hx5 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5hx5 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ABC3F_HUMAN ABC3F_HUMAN] DNA deaminase (cytidine deaminase) which acts as an inhibitor of retrovirus replication and retrotransposon mobility via deaminase-dependent and -independent mechanisms. Exhibits antiviral activity against vif-deficient HIV-1. After the penetration of retroviral nucleocapsids into target cells of infection and the initiation of reverse transcription, it can induce the conversion of cytosine to uracil in the minus-sense single-strand viral DNA, leading to G-to-A hypermutations in the subsequent plus-strand viral DNA. The resultant detrimental levels of mutations in the proviral genome, along with a deamination-independent mechanism that works prior to the proviral integration, together exert efficient antiretroviral effects in infected target cells. Selectively targets single-stranded DNA and does not deaminate double-stranded DNA or single- or double-stranded RNA. Exhibits antiviral activity also against hepatitis B virus (HBV), equine infectious anemia virus (EIAV), xenotropic MuLV-related virus (XMRV) and simian foamy virus (SFV) and may inhibit the mobility of LTR and non-LTR retrotransposons. May also play a role in the epigenetic regulation of gene expression through the process of active DNA demethylation.<ref>PMID:15152192</ref> <ref>PMID:16527742</ref> <ref>PMID:16378963</ref> <ref>PMID:19458006</ref> <ref>PMID:20219927</ref> <ref>PMID:20335265</ref> <ref>PMID:20062055</ref> <ref>PMID:21496894</ref> <ref>PMID:21835787</ref> <ref>PMID:22915799</ref> <ref>PMID:22807680</ref> <ref>PMID:23097438</ref> <ref>PMID:23152537</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The APOBEC3 family of DNA cytosine deaminases is capable of restricting the replication of HIV-1 and other pathogens. Here, we report a 1.92 A resolution crystal structure of the Vif-binding and catalytic domain of APOBEC3F (A3F). This structure is distinct from the previously published APOBEC and phylogenetically related deaminase structures, as it is the first without zinc in the active site. We determined an additional structure containing zinc in the same crystal form that allows direct comparison with the zinc-free structure. In the absence of zinc, the conserved active site residues that normally participate in zinc coordination show unique conformations, including a 90 degree rotation of His249 and disulfide bond formation between Cys280 and Cys283. We found that zinc coordination is influenced by pH, and treating the protein at low pH in crystallization buffer is sufficient to remove zinc. Zinc coordination and catalytic activity are reconstituted with the addition of zinc only in a reduced environment likely due to the two active site cysteines readily forming a disulfide bond when not coordinating zinc. We show that the enzyme is active in the presence of zinc and cobalt but not with other divalent metals. These results unexpectedly demonstrate that zinc is not required for the structural integrity of A3F and suggest that metal coordination may be a strategy for regulating the activity of A3F and related deaminases.

1.92 Angstrom Zinc-Free APOBEC3F Catalytic Domain Crystal Structure.,Shaban NM, Shi K, Li M, Aihara H, Harris RS J Mol Biol. 2016 Jun 5;428(11):2307-16. doi: 10.1016/j.jmb.2016.04.026. Epub 2016, Apr 30. PMID:27139641<ref>PMID:27139641</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5hx5" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Aihara H]]
[[Category: Harris RS]]
[[Category: Shaban NM]]
[[Category: Shi K]]