View source for 6zmg


==PHAGE SAM LYASE IN COMPLEX WITH S-ADENOSYL-L-HOMOCYSTEINE==
<StructureSection load='6zmg' size='340' side='right'caption='[[6zmg]], [[Resolution|resolution]] 1.48&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6ZMG OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6ZMG 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]] 1.48&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene>, <scene name='pdbligand=SAH:S-ADENOSYL-L-HOMOCYSTEINE'>SAH</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=6zmg FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6zmg OCA], [https://pdbe.org/6zmg PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6zmg RCSB], [https://www.ebi.ac.uk/pdbsum/6zmg PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6zmg ProSAT]</span></td></tr>
</table>
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== Publication Abstract from PubMed ==
The first S-adenosyl methionine (SAM) degrading enzyme (SAMase) was discovered in bacteriophage T3, as a counter-defense against the bacterial restriction-modification system, and annotated as a SAM hydrolase forming 5'-methyl-thioadenosine (MTA) and L-homoserine. From environmental phages, we recently discovered three SAMases with barely detectable sequence similarity to T3 SAMase and without homology to proteins of known structure. Here, we present the very first phage SAMase structures, in complex with a substrate analogue and the product MTA. The structure shows a trimer of alpha-beta sandwiches similar to the GlnB-like superfamily, with active sites formed at the trimer interfaces. Quantum-mechanical calculations, thin-layer chromatography, and nuclear magnetic resonance spectroscopy demonstrate that this family of enzymes are not hydrolases but lyases forming MTA and L-homoserine lactone in a unimolecular reaction mechanism. Sequence analysis and in vitro and in vivo mutagenesis support that T3 SAMase belongs to the same structural family and utilizes the same reaction mechanism.

Structure and mechanism of a phage-encoded SAM lyase revises catalytic function of enzyme family.,Guo X, Soderholm A, Kanchugal P S, Isaksen GV, Warsi O, Eckhard U, Triguis S, Gogoll A, Jerlstrom-Hultqvist J, Aqvist J, Andersson DI, Selmer M Elife. 2021 Feb 10;10. pii: 61818. doi: 10.7554/eLife.61818. PMID:33567250<ref>PMID:33567250</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6zmg" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Guo X]]
[[Category: Kanchugal P S]]
[[Category: Selmer M]]