5tl4: Difference between revisions

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<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=5tl4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5tl4 OCA], [http://pdbe.org/5tl4 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5tl4 RCSB], [http://www.ebi.ac.uk/pdbsum/5tl4 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5tl4 ProSAT]</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=5tl4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5tl4 OCA], [http://pdbe.org/5tl4 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5tl4 RCSB], [http://www.ebi.ac.uk/pdbsum/5tl4 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5tl4 ProSAT]</span></td></tr>
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== Publication Abstract from PubMed ==
Some strains of soil and marine bacteria have evolved intricate metabolic pathways for using environmentally derived aromatics as a carbon source. Many of these metabolic pathways go through intermediates such as vanillate, 3-O-methylgallate, and syringate. Demethylation of these compounds is essential for downstream aryl modification, ring opening, and subsequent assimilation of these compounds into the tricarboxylic acid (TCA) cycle, and, correspondingly, there are a variety of associated aryl demethylase systems that vary in complexity. Intriguingly, only a basic understanding of the least complex system, the tetrahydrofolate-dependent aryl demethylase LigM from Sphingomonas paucimobilis, a bacterial strain that metabolizes lignin-derived aromatics, was previously available. LigM-catalyzed demethylation enables further modification and ring opening of the single-ring aromatics vanillate and 3-O-methylgallate, which are common byproducts of biofuel production. Here, we characterize aryl O-demethylation by LigM and report its 1.81-A crystal structure, revealing a unique demethylase fold and a canonical folate-binding domain. Structural homology and geometry optimization calculations enabled the identification of LigM's tetrahydrofolate-binding site and protein-folate interactions. Computationally guided mutagenesis and kinetic analyses allowed the identification of the enzyme's aryl-binding site location and determination of its unique, catalytic tyrosine-dependent reaction mechanism. This work defines LigM as a distinct demethylase, both structurally and functionally, and provides insight into demethylation and its reaction requirements. These results afford the mechanistic details required for efficient utilization of LigM as a tool for aryl O-demethylation and as a component of synthetic biology efforts to valorize previously underused aromatic compounds.
Structure of aryl O-demethylase offers molecular insight into a catalytic tyrosine-dependent mechanism.,Kohler AC, Mills MJ, Adams PD, Simmons BA, Sale KL Proc Natl Acad Sci U S A. 2017 Apr 3. pii: 201619263. doi:, 10.1073/pnas.1619263114. PMID:28373573<ref>PMID:28373573</ref>
From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
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