View source for 3fsb


==Crystal structure of QdtC, the dTDP-3-amino-3,6-dideoxy-D-glucose N-acetyl transferase from Thermoanaerobacterium thermosaccharolyticum in complex with CoA and dTDP-3-amino-quinovose==
<StructureSection load='3fsb' size='340' side='right'caption='[[3fsb]], [[Resolution|resolution]] 1.95&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3fsb]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Thermoanaerobacterium_thermosaccharolyticum Thermoanaerobacterium thermosaccharolyticum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3FSB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3FSB 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]] 1.95&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=COA:COENZYME+A'>COA</scene>, <scene name='pdbligand=T3Q:[(3R,4S,5S,6R)-4-AMINO-3,5-DIHYDROXY-6-METHYLOXAN-2-YL][HYDROXY-[[(2R,3S,5R)-3-HYDROXY-5-(5-METHYL-2,4-DIOXOPYRIMIDIN-1-YL)OXOLAN-2-YL]METHOXY]PHOSPHORYL]+HYDROGEN+PHOSPHATE'>T3Q</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=3fsb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3fsb OCA], [https://pdbe.org/3fsb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3fsb RCSB], [https://www.ebi.ac.uk/pdbsum/3fsb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3fsb ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q6TFC6_THETR Q6TFC6_THETR] 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/fs/3fsb_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=3fsb ConSurf].
<div style="clear:both"></div>
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== Publication Abstract from PubMed ==
3-acetamido-3,6-didexoy-alpha-D-glucose or Quip3NAc is an unusual dideoxy sugar found in the O-antigens of various Gram-negative bacteria and in the S-layer glycoprotein glycans of some Gram-positive bacteria. It is produced in these organisms as a dTDP-linked sugar, with five enzymes ultimately required for its biosynthesis. The focus of this investigation is on the enzyme QdtC, a CoA-dependent N-acetyltransferase that catalyzes the last step in the Quip3NAc biosynthetic pathway. For this analysis, three crystal structures were determined: the wild-type enzyme in the presence of acetyl-CoA, and two ternary complexes of the enzyme with CoA and either dTDP-D-Quip3NAc or dTDP-3-amino-3,6-didexoy-alphalpha-D-galactose (dTDP-D-Fucp3N). Each subunit of the trimeric enzyme is dominated by a left-handed beta-helix motif with 11 turns. The three active sites are located at the subunit:subunit interfaces, and the two dTDP-sugar ligands employed in this study bind to the protein in nearly identical manners. Those residues responsible for anchoring the hexose moieties of the dTDP-sugars to the protein include Glu 141, Asn 159, Asp 160 from one subunit and His 134 from another subunit. To probe the roles of various amino acid residues in the catalytic mechanism of the enzyme, ten site-directed mutant proteins were constructed and their kinetic parameters measured. On the basis of these data, a catalytic mechanism is proposed for QdtC whereby the acetylation of the sugar amino group does not require a catalytic base provided by the protein. Rather, the sulfur of CoA functions as the ultimate proton acceptor.

Structural and Functional Studies of QdtC: an N-Acetyltransferase Required for the Biosynthesis of dTDP-3-Acetamido-3,6-Dideoxy--D-Glucose.,Thoden J, Cook P, Schaffer C, Messner P, Holden H Biochemistry. 2009 Feb 4. PMID:19191736<ref>PMID:19191736</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 3fsb" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Thermoanaerobacterium thermosaccharolyticum]]
[[Category: Holden HM]]
[[Category: Thoden JB]]