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[[ | ==MycE Methyltransferase from the Mycinamycin Biosynthetic Pathway in Complex with Mg and SAH, Crystal form 2== | ||
<StructureSection load='3sso' size='340' side='right' caption='[[3sso]], [[Resolution|resolution]] 1.90Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[3sso]] is a 6 chain structure with sequence from [http://en.wikipedia.org/wiki/Micromonospora_griseorubida Micromonospora griseorubida]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3SSO OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3SSO FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=SAH:S-ADENOSYL-L-HOMOCYSTEINE'>SAH</scene><br> | |||
<tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3ssm|3ssm]], [[3ssn|3ssn]]</td></tr> | |||
<tr><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">mycE ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=28040 Micromonospora griseorubida])</td></tr> | |||
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3sso FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3sso OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3sso RCSB], [http://www.ebi.ac.uk/pdbsum/3sso PDBsum]</span></td></tr> | |||
<table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
O-linked methylation of sugar substituents is a common modification in the biosynthesis of many natural products and is catalyzed by multiple families of S-adenosyl-L-methionine (SAM or AdoMet)-dependent methyltransferases (MTs). Mycinamicins, potent antibiotics from Micromonospora griseorubida, can be methylated at two positions on a 6-deoxyallose substituent. The first methylation is catalyzed by MycE, a SAM- and metal-dependent MT. Crystal structures were determined for MycE bound to the product S-adenosyl-L-homocysteine (AdoHcy) and magnesium, both with and without the natural substrate mycinamicin VI. This represents the first structure of a natural product sugar MT in complex with its natural substrate. MycE is a tetramer of a two-domain polypeptide, comprising a C-terminal catalytic MT domain and an N-terminal auxiliary domain, which is important for quaternary assembly and for substrate binding. The symmetric MycE tetramer has a novel MT organization in which each of the four active sites is formed at the junction of three monomers within the tetramer. The active-site structure supports a mechanism in which a conserved histidine acts as a general base, and the metal ion helps to position the methyl acceptor and to stabilize a hydroxylate intermediate. A conserved tyrosine is suggested to support activity through interactions with the transferred methyl group from the SAM methyl donor. The structure of the free enzyme reveals a dramatic order-disorder transition in the active site relative to the S-adenosyl-L-homocysteine complexes, suggesting a mechanism for product/substrate exchange through concerted movement of five loops and the polypeptide C-terminus. | |||
A new structural form in the SAM/metal-dependent omethyltransferase family: MycE from the mycinamicin biosynthetic pathway.,Akey DL, Li S, Konwerski JR, Confer LA, Bernard SM, Anzai Y, Kato F, Sherman DH, Smith JL J Mol Biol. 2011 Oct 21;413(2):438-50. Epub 2011 Aug 23. PMID:21884704<ref>PMID:21884704</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
== | |||
< | |||
[[Category: Micromonospora griseorubida]] | [[Category: Micromonospora griseorubida]] | ||
[[Category: Akey, D L.]] | [[Category: Akey, D L.]] | ||
Revision as of 08:30, 5 June 2014
MycE Methyltransferase from the Mycinamycin Biosynthetic Pathway in Complex with Mg and SAH, Crystal form 2MycE Methyltransferase from the Mycinamycin Biosynthetic Pathway in Complex with Mg and SAH, Crystal form 2
Structural highlights
Publication Abstract from PubMedO-linked methylation of sugar substituents is a common modification in the biosynthesis of many natural products and is catalyzed by multiple families of S-adenosyl-L-methionine (SAM or AdoMet)-dependent methyltransferases (MTs). Mycinamicins, potent antibiotics from Micromonospora griseorubida, can be methylated at two positions on a 6-deoxyallose substituent. The first methylation is catalyzed by MycE, a SAM- and metal-dependent MT. Crystal structures were determined for MycE bound to the product S-adenosyl-L-homocysteine (AdoHcy) and magnesium, both with and without the natural substrate mycinamicin VI. This represents the first structure of a natural product sugar MT in complex with its natural substrate. MycE is a tetramer of a two-domain polypeptide, comprising a C-terminal catalytic MT domain and an N-terminal auxiliary domain, which is important for quaternary assembly and for substrate binding. The symmetric MycE tetramer has a novel MT organization in which each of the four active sites is formed at the junction of three monomers within the tetramer. The active-site structure supports a mechanism in which a conserved histidine acts as a general base, and the metal ion helps to position the methyl acceptor and to stabilize a hydroxylate intermediate. A conserved tyrosine is suggested to support activity through interactions with the transferred methyl group from the SAM methyl donor. The structure of the free enzyme reveals a dramatic order-disorder transition in the active site relative to the S-adenosyl-L-homocysteine complexes, suggesting a mechanism for product/substrate exchange through concerted movement of five loops and the polypeptide C-terminus. A new structural form in the SAM/metal-dependent omethyltransferase family: MycE from the mycinamicin biosynthetic pathway.,Akey DL, Li S, Konwerski JR, Confer LA, Bernard SM, Anzai Y, Kato F, Sherman DH, Smith JL J Mol Biol. 2011 Oct 21;413(2):438-50. Epub 2011 Aug 23. PMID:21884704[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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