View source for 1z74

==Crystal Structure of E.coli ArnA dehydrogenase (decarboxylase) domain, R619Y mutant==
<StructureSection load='1z74' size='340' side='right' caption='[[1z74]], [[Resolution|resolution]] 2.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1z74]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/"bacillus_coli"_migula_1895 "bacillus coli" migula 1895]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1Z74 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1Z74 FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1z73|1z73]], [[1z75|1z75]], [[1z7b|1z7b]], [[1z7e|1z7e]]</td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">PMRI, YFBG ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 "Bacillus coli" Migula 1895])</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=1z74 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1z74 OCA], [http://pdbe.org/1z74 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1z74 RCSB], [http://www.ebi.ac.uk/pdbsum/1z74 PDBsum]</span></td></tr>
</table>
== Function ==
[[http://www.uniprot.org/uniprot/ARNA_ECOLI ARNA_ECOLI]] Bifunctional enzyme that catalyzes the oxidative decarboxylation of UDP-glucuronic acid (UDP-GlcUA) to UDP-4-keto-arabinose (UDP-Ara4O) and the addition of a formyl group to UDP-4-amino-4-deoxy-L-arabinose (UDP-L-Ara4N) to form UDP-L-4-formamido-arabinose (UDP-L-Ara4FN). The modified arabinose is attached to lipid A and is required for resistance to polymyxin and cationic antimicrobial peptides.<ref>PMID:11706007</ref> <ref>PMID:15695810</ref>  
== 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/z7/1z74_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/chain_selection.php?pdb_ID=2ata ConSurf].
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== Publication Abstract from PubMed ==
The modification of lipid A with 4-amino-4-deoxy-L-arabinose (Ara4N) allows gram-negative bacteria to resist the antimicrobial activity of cationic antimicrobial peptides and antibiotics such as polymyxin. ArnA is the first enzyme specific to the lipid A-Ara4N pathway. It contains two functionally and physically separable domains: a dehydrogenase domain (ArnA_DH) catalyzing the NAD+-dependent oxidative decarboxylation of UDP-Glucuronic acid (UDP-GlcA), and a transformylase domain that formylates UDP-Ara4N. Here, we describe the crystal structure of the full-length bifunctional ArnA with UDP-GlcA and ATP bound to the dehydrogenase domain. Binding of UDP-GlcA triggers a 17 A conformational change in ArnA_DH that opens the NAD+ binding site while trapping UDP-GlcA. We propose an ordered mechanism of substrate binding and product release. Mutation of residues R619 and S433 demonstrates their importance in catalysis and suggests that R619 functions as a general acid in catalysis. The proposed mechanism for ArnA_DH has important implications for the design of selective inhibitors.

Structure and mechanism of ArnA: conformational change implies ordered dehydrogenase mechanism in key enzyme for polymyxin resistance.,Gatzeva-Topalova PZ, May AP, Sousa MC Structure. 2005 Jun;13(6):929-42. PMID:15939024<ref>PMID:15939024</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 1z74" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Bacillus coli migula 1895]]
[[Category: Gatzeva-Topalova, P Z]]
[[Category: May, A P]]
[[Category: Sousa, M C]]
[[Category: Hydrolase]]
[[Category: Rossmann fold]]