3sso: Difference between revisions

<StructureSection load='3sso' size='340' side='right' caption='[[3sso]], [[Resolution|resolution]] 1.90&Aring;' scene=''>

<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 id='ligand'><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></td></tr>

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3ssm|3ssm]], [[3ssn|3ssn]]</td></tr>

<tr id='gene'><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 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=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>

== 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>

[[Category: Akey, D L.]]

[[Category: Smith, J L.]]

[[Category: Transferase]]