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==Ribonucleotide Reductase R2 protein from Aquifex aeolicus==
<StructureSection load='7aik' size='340' side='right'caption='[[7aik]], [[Resolution|resolution]] 2.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7aik]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Aquifex_aeolicus_VF5 Aquifex aeolicus VF5]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7AIK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7AIK 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]] 2.1&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=FE2:FE+(II)+ION'>FE2</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=7aik FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7aik OCA], [https://pdbe.org/7aik PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7aik RCSB], [https://www.ebi.ac.uk/pdbsum/7aik PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7aik ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/RIR2_AQUAE RIR2_AQUAE] Provides the precursors necessary for DNA synthesis. Catalyzes the biosynthesis of deoxyribonucleotides from the corresponding ribonucleotides (By similarity).
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Ribonucleotide reductase (RNR) is an essential enzyme with a complex mechanism of allosteric regulation found in nearly all living organisms. Class I RNRs are composed of two proteins, a large alpha-subunit (R1) and a smaller beta-subunit (R2) that exist as homodimers, that combine to form an active heterotetramer. Aquifex aeolicus is a hyperthermophilic bacterium with an unusual RNR encoding a 346-residue intein in the DNA sequence encoding its R2 subunit. We present the first structures of the A. aeolicus R1 and R2 (AaR1 and AaR2, respectively) proteins as well as the biophysical and biochemical characterization of active and inactive A. aeolicus RNR. While the active oligomeric state and activity regulation of A. aeolicus RNR are similar to those of other characterized RNRs, the X-ray crystal structures also reveal distinct features and adaptations. Specifically, AaR1 contains a beta-hairpin hook structure at the dimer interface, which has an interesting pi-stacking interaction absent in other members of the NrdAh subclass, and its ATP cone houses two ATP molecules. We determined structures of two AaR2 proteins: one purified from a construct lacking the intein (AaR2) and a second purified from a construct including the intein sequence (AaR2_genomic). These structures in the context of metal content analysis and activity data indicate that AaR2_genomic displays much higher iron occupancy and activity compared to AaR2, suggesting that the intein is important for facilitating complete iron incorporation, particularly in the Fe2 site of the mature R2 protein, which may be important for the survival of A. aeolicus in low-oxygen environments.

Structural and Biochemical Investigation of Class I Ribonucleotide Reductase from the Hyperthermophile Aquifex aeolicus.,Rehling D, Scaletti ER, Rozman Grinberg I, Lundin D, Sahlin M, Hofer A, Sjoberg BM, Stenmark P Biochemistry. 2022 Jan 18;61(2):92-106. doi: 10.1021/acs.biochem.1c00503. Epub, 2021 Dec 23. PMID:34941255<ref>PMID:34941255</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 7aik" style="background-color:#fffaf0;"></div>

==See Also==
*[[Ribonucleotide reductase 3D structures|Ribonucleotide reductase 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Aquifex aeolicus VF5]]
[[Category: Large Structures]]
[[Category: Rehling D]]
[[Category: Scaletti ER]]
[[Category: Stenmark P]]