View source for 5ul4


==Structure of Cobalamin-dependent S-adenosylmethionine radical enzyme OxsB with aqua-cobalamin and S-adenosylmethionine bound==
<StructureSection load='5ul4' size='340' side='right'caption='[[5ul4]], [[Resolution|resolution]] 1.85&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5ul4]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Priestia_megaterium Priestia megaterium]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5UL4 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5UL4 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=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=MES:2-(N-MORPHOLINO)-ETHANESULFONIC+ACID'>MES</scene>, <scene name='pdbligand=SAM:S-ADENOSYLMETHIONINE'>SAM</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=5ul4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5ul4 OCA], [https://pdbe.org/5ul4 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5ul4 RCSB], [https://www.ebi.ac.uk/pdbsum/5ul4 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5ul4 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/OXSB_PRIMG OXSB_PRIMG] Isomerase involved in the biosynthesis of oxetanocin A (OXT-A), a nucleoside analog with antitumor, antiviral and antibacterial properties (PubMed:28346939, PubMed:33560833). Catalyzes an oxidative ring contraction of dAMP, forming an oxetane aldehyde (PubMed:28346939, PubMed:33560833). In addition, shows methyltransferase activity in vitro and is able to catalyze the radical mediated, stereoselective C2'-methylation of dAMP to form methylated 2'-dAMP (PubMed:33560833, PubMed:36719327). Also catalyzes the demethylation of S-adenosyl-L-methionine (SAM) to S-adenosyl-L-homocysteine (SAH) (PubMed:33560833).<ref>PMID:28346939</ref> <ref>PMID:33560833</ref> <ref>PMID:36719327</ref> 
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== Publication Abstract from PubMed ==
Oxetanocin A (OXT-A) is a potent antitumour, antiviral and antibacterial compound. Biosynthesis of OXT-A has been linked to a plasmid-borne Bacillus megaterium gene cluster that contains four genes: oxsA, oxsB, oxrA and oxrB. Here we show that both the oxsA and oxsB genes are required for the production of OXT-A. Biochemical analysis of the encoded proteins, a cobalamin (Cbl)-dependent S-adenosylmethionine (AdoMet) radical enzyme, OxsB, and an HD-domain phosphohydrolase, OxsA, reveals that OXT-A is derived from a 2'-deoxyadenosine phosphate in an OxsB-catalysed ring contraction reaction initiated by hydrogen atom abstraction from C2'. Hence, OxsB represents the first biochemically characterized non-methylating Cbl-dependent AdoMet radical enzyme. X-ray analysis of OxsB reveals the fold of a Cbl-dependent AdoMet radical enzyme, a family of enzymes with an estimated 7,000 members. Overall, this work provides a framework for understanding the interplay of AdoMet and Cbl cofactors and expands the catalytic repertoire of Cbl-dependent AdoMet radical enzymes.

A B12-dependent radical SAM enzyme involved in oxetanocin A biosynthesis.,Bridwell-Rabb J, Zhong A, Sun HG, Drennan CL, Liu HW Nature. 2017 Mar 27. doi: 10.1038/nature21689. PMID:28346939<ref>PMID:28346939</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5ul4" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Priestia megaterium]]
[[Category: Bridwell-Rabb J]]
[[Category: Drennan CL]]