4gek

<StructureSection load='4gek' size='340' side='right' caption='[[4gek]], [[Resolution|resolution]] 1.50&Aring;' scene=''>

<table><tr><td colspan='2'>[[4gek]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Escherichia_coli_uti89 Escherichia coli uti89]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4GEK OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4GEK FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=GEK:(2S)-4-[{[(2S,3S,4R,5R)-5-(6-AMINO-9H-PURIN-9-YL)-3,4-DIHYDROXYTETRAHYDROFURAN-2-YL]METHYL}(CARBOXYLATOMETHYL)SULFONIO]-2-AMMONIOBUTANOATE'>GEK</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>

<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">cmoA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=364106 Escherichia coli UTI89])</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=4gek FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4gek OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4gek RCSB], [http://www.ebi.ac.uk/pdbsum/4gek PDBsum]</span></td></tr>

<div style="background-color:#fffaf0;">

== Publication Abstract from PubMed ==

The identification of novel metabolites and the characterization of their biological functions are major challenges in biology. X-ray crystallography can reveal unanticipated ligands that persist through purification and crystallization. These adventitious protein-ligand complexes provide insights into new activities, pathways and regulatory mechanisms. We describe a new metabolite, carboxy-S-adenosyl-l-methionine (Cx-SAM), its biosynthetic pathway and its role in transfer RNA modification. The structure of CmoA, a member of the SAM-dependent methyltransferase superfamily, revealed a ligand consistent with Cx-SAM in the catalytic site. Mechanistic analyses showed an unprecedented role for prephenate as the carboxyl donor and the involvement of a unique ylide intermediate as the carboxyl acceptor in the CmoA-mediated conversion of SAM to Cx-SAM. A second member of the SAM-dependent methyltransferase superfamily, CmoB, recognizes Cx-SAM and acts as a carboxymethyltransferase to convert 5-hydroxyuridine into 5-oxyacetyl uridine at the wobble position of multiple tRNAs in Gram-negative bacteria, resulting in expanded codon-recognition properties. CmoA and CmoB represent the first documented synthase and transferase for Cx-SAM. These findings reveal new functional diversity in the SAM-dependent methyltransferase superfamily and expand the metabolic and biological contributions of SAM-based biochemistry. These discoveries highlight the value of structural genomics approaches in identifying ligands within the context of their physiologically relevant macromolecular binding partners, and in revealing their functions.

 

Structure-guided discovery of the metabolite carboxy-SAM that modulates tRNA function.,Kim J, Xiao H, Bonanno JB, Kalyanaraman C, Brown S, Tang X, Al-Obaidi NF, Patskovsky Y, Babbitt PC, Jacobson MP, Lee YS, Almo SC Nature. 2013 May 15. doi: 10.1038/nature12180. PMID:23676670<ref>PMID:23676670</ref>

 

*[[TRNA methyltransferase|TRNA methyltransferase]]

[[Category: Escherichia coli uti89]]

[[Category: Almo, S C]]

[[Category: Bhosle, R]]

[[Category: Bonanno, J B]]

[[Category: Kim, J]]

[[Category: Structural genomic]]

[[Category: Sampathkumar, P]]

[[Category: Toro, R]]

[[Category: Transferase]]