View source for 5d08


==Crystal structure of selenomethionine-labeled epoxyqueuosine reductase==
<StructureSection load='5d08' size='340' side='right'caption='[[5d08]], [[Resolution|resolution]] 1.75&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5d08]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Bacsu Bacsu]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5D08 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5D08 FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=B12:COBALAMIN'>B12</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene>, <scene name='pdbligand=SF4:IRON/SULFUR+CLUSTER'>SF4</scene></td></tr>
<tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[5d0a|5d0a]], [[5d0b|5d0b]]</td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">queG, ygaP, yhbA, BSU08910 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=224308 BACSU])</td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Epoxyqueuosine_reductase Epoxyqueuosine reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.17.99.6 1.17.99.6] </span></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5d08 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5d08 OCA], [http://pdbe.org/5d08 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5d08 RCSB], [http://www.ebi.ac.uk/pdbsum/5d08 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5d08 ProSAT]</span></td></tr>
</table>
== Function ==
[[http://www.uniprot.org/uniprot/QUEG_BACSU QUEG_BACSU]] Catalyzes the conversion of epoxyqueuosine (oQ) to queuosine (Q), which is a hypermodified base found in the wobble positions of tRNA(Asp), tRNA(Asn), tRNA(His) and tRNA(Tyr).[HAMAP-Rule:MF_00916]<ref>PMID:21502530</ref>  
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Queuosine (Q) was discovered in the wobble position of a transfer RNA (tRNA) 47 years ago, yet the final biosynthetic enzyme responsible for Q-maturation, epoxyqueuosine (oQ) reductase (QueG), was only recently identified. QueG is a cobalamin (Cbl)-dependent, [4Fe-4S] cluster-containing protein that produces the hypermodified nucleoside Q in situ on four tRNAs. To understand how QueG is able to perform epoxide reduction, an unprecedented reaction for a Cbl-dependent enzyme, we have determined a series of high resolution structures of QueG from Bacillus subtilis Our structure of QueG bound to a tRNATyr anticodon stem loop shows how this enzyme uses a HEAT-like domain to recognize the appropriate anticodons and position the hypermodified nucleoside into the enzyme active site. We find Q bound directly above the Cbl, consistent with a reaction mechanism that involves the formation of a covalent Cbl-tRNA intermediate. Using protein film electrochemistry, we show that two [4Fe-4S] clusters adjacent to the Cbl have redox potentials in the range expected for Cbl reduction, suggesting how Cbl can be activated for nucleophilic attack on oQ. Together, these structural and electrochemical data inform our understanding of Cbl dependent nucleic acid modification.

Molecular basis of cobalamin-dependent RNA modification.,Dowling DP, Miles ZD, Kohrer C, Maiocco SJ, Elliott SJ, Bandarian V, Drennan CL Nucleic Acids Res. 2016 Sep 15. pii: gkw806. PMID:27638883<ref>PMID:27638883</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5d08" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Bacsu]]
[[Category: Epoxyqueuosine reductase]]
[[Category: Large Structures]]
[[Category: Bandarian, V]]
[[Category: Dowling, D P]]
[[Category: Drennan, C L]]
[[Category: Kohrer, C]]
[[Category: Miles, Z D]]
[[Category: B12]]
[[Category: Heat-domain]]
[[Category: Oxidoreductase]]
[[Category: Queuosine]]
[[Category: Trna modification]]