View source for 4els


==Structure of E. Coli. 1,4-dihydroxy-2- naphthoyl coenzyme A synthases (MENB) in complex with bicarbonate==
<StructureSection load='4els' size='340' side='right'caption='[[4els]], [[Resolution|resolution]] 2.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4els]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4ELS OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4ELS 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]] 2.303&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BCT:BICARBONATE+ION'>BCT</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=PEG:DI(HYDROXYETHYL)ETHER'>PEG</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=4els FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4els OCA], [https://pdbe.org/4els PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4els RCSB], [https://www.ebi.ac.uk/pdbsum/4els PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4els ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/MENB_ECOLI MENB_ECOLI] Converts o-succinylbenzoyl-CoA (OSB-CoA) to 1,4-dihydroxy-2-naphthoyl-CoA (DHNA-CoA).<ref>PMID:1091286</ref> <ref>PMID:20643650</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
1,4-Dihydroxy-2-naphthoyl coenzyme A (DHNA-CoA) synthase, or MenB, catalyzes a carbon-carbon bond formation reaction in the biosynthesis of both vitamin K1 and K2. Bicarbonate is crucial to the activity of a large subset of its orthologues but lacks a clearly defined structural and mechanistic role. Here we determine the crystal structure of the holoenzymes from Escherichia coli at 2.30 A and Synechocystis sp. PCC6803 at 2.04 A, in which the bicarbonate cofactor is bound to the enzyme active site at a position equivalent to that of the side chain carboxylate of an aspartate residue conserved among bicarbonate-insensitive DHNA-CoA synthases. Binding of the planar anion involves both nonspecific electrostatic attraction and specific hydrogen bonding and hydrophobic interactions. In the absence of bicarbonate, the anion binding site is occupied by a chloride ion or nitrate, an inhibitor directly competing with bicarbonate. These results provide a solid structural basis for the bicarbonate dependence of the enzymatic activity of type I DHNA-CoA synthases. The unique location of the bicarbonate ion in relation to the expected position of the substrate alpha-proton in the enzyme's active site suggests a critical catalytic role for the anionic cofactor as a catalytic base in enolate formation.

Active Site Binding and Catalytic Role of Bicarbonate in 1,4-Dihydroxy-2-naphthoyl Coenzyme A Synthases from Vitamin K Biosynthetic Pathways.,Sun Y, Song H, Li J, Jiang M, Li Y, Zhou J, Guo Z Biochemistry. 2012 May 24. PMID:22606952<ref>PMID:22606952</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4els" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Guo ZH]]
[[Category: Jiang M]]
[[Category: Li J]]
[[Category: Li Y]]
[[Category: Song HG]]
[[Category: Sun YR]]
[[Category: Zhou JH]]