View source for 4s26


==Crystal structure of Arabidopsis thaliana ThiC with bound imidazole ribonucleotide, S-adenosylhomocysteine, Fe4S4 cluster and Zn (monoclinic crystal form)==
<StructureSection load='4s26' size='340' side='right'caption='[[4s26]], [[Resolution|resolution]] 1.85&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4s26]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Arabidopsis_thaliana Arabidopsis thaliana]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4S26 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4S26 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]] 1.85&#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=IRN:1-(5-O-PHOSPHONO-BETA-D-RIBOFURANOSYL)-1H-IMIDAZOLE'>IRN</scene>, <scene name='pdbligand=SAH:S-ADENOSYL-L-HOMOCYSTEINE'>SAH</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=4s26 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4s26 OCA], [https://pdbe.org/4s26 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4s26 RCSB], [https://www.ebi.ac.uk/pdbsum/4s26 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4s26 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/THIC_ARATH THIC_ARATH] Catalyzes the synthesis of the hydroxymethylpyrimidine phosphate (HMP-P) moiety of thiamine from aminoimidazole ribotide (AIR) in a radical S-adenosyl-L-methionine (SAM)-dependent reaction.<ref>PMID:18048325</ref> <ref>PMID:18332905</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Radical S-adenosylmethionine (SAM) enzymes use a [4Fe-4S] cluster to generate a 5'-deoxyadenosyl radical. Canonical radical SAM enzymes are characterized by a beta-barrel-like fold and SAM anchors to the differentiated iron of the cluster, which is located near the amino terminus and within the beta-barrel, through its amino and carboxylate groups. Here we show that ThiC, the thiamin pyrimidine synthase in plants and bacteria, contains a tethered cluster-binding domain at its carboxy terminus that moves in and out of the active site during catalysis. In contrast to canonical radical SAM enzymes, we predict that SAM anchors to an additional active site metal through its amino and carboxylate groups. Superimposition of the catalytic domains of ThiC and glutamate mutase shows that these two enzymes share similar active site architectures, thus providing strong evidence for an evolutionary link between the radical SAM and adenosylcobalamin-dependent enzyme superfamilies.

Non-canonical active site architecture of the radical SAM thiamin pyrimidine synthase.,Fenwick MK, Mehta AP, Zhang Y, Abdelwahed SH, Begley TP, Ealick SE Nat Commun. 2015 Mar 27;6:6480. doi: 10.1038/ncomms7480. PMID:25813242<ref>PMID:25813242</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4s26" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Arabidopsis thaliana]]
[[Category: Large Structures]]
[[Category: Abdelwahed S]]
[[Category: Begley TP]]
[[Category: Ealick SE]]
[[Category: Fenwick MK]]
[[Category: Mehta AP]]
[[Category: Zhang Y]]