View source for 2ar8


==The structure of tryptophan 7-halogenase (PrnA)suggests a mechanism for regioselective chlorination==
<StructureSection load='2ar8' size='340' side='right'caption='[[2ar8]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2ar8]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Pseudomonas_fluorescens Pseudomonas fluorescens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2AR8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2AR8 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]] 2.2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=CTE:7-CHLOROTRYPTOPHAN'>CTE</scene>, <scene name='pdbligand=FAD:FLAVIN-ADENINE+DINUCLEOTIDE'>FAD</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=2ar8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2ar8 OCA], [https://pdbe.org/2ar8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2ar8 RCSB], [https://www.ebi.ac.uk/pdbsum/2ar8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2ar8 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/PRNA_PSEFL PRNA_PSEFL] Involved in the biosynthesis of the antifungal antibiotic pyrrolnitrin. Catalyze the chlorination of tryptophan (Trp) at C7 position to yield 7-chloro-L-tryptophan (7-CLT). The reaction between FADH2, Cl-, and O2 generates the powerful oxidant HOCl, which is presumed to carry out the chlorination reaction. The reaction of HOCl with the active site Lys-79 generates a lysine chloramine, which plays a key role in directing regiospecific chlorination of substrate in this important class of biosynthetic enzymes. It is also able to use bromide ions to generate monobrominated Trp.<ref>PMID:10941070</ref> <ref>PMID:9172332</ref> <ref>PMID:9537395</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/ar/2ar8_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=2ar8 ConSurf].
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== Publication Abstract from PubMed ==
Chlorinated natural products include vancomycin and cryptophycin A. Their biosynthesis involves regioselective chlorination by flavin-dependent halogenases. We report the structural characterization of tryptophan 7-halogenase (PrnA), which regioselectively chlorinates tryptophan. Tryptophan and flavin adenine dinucleotide (FAD) are separated by a 10 angstrom-long tunnel and bound by distinct enzyme modules. The FAD module is conserved in halogenases and is related to flavin-dependent monooxygenases. On the basis of biochemical studies, crystal structures, and by analogy with monooxygenases, we predict that FADH2 reacts with O2 to make peroxyflavin, which is decomposed by Cl-. The resulting HOCl is guided through the tunnel to tryptophan, where it is activated to participate in electrophilic aromatic substitution.

Tryptophan 7-halogenase (PrnA) structure suggests a mechanism for regioselective chlorination.,Dong C, Flecks S, Unversucht S, Haupt C, van Pee KH, Naismith JH Science. 2005 Sep 30;309(5744):2216-9. PMID:16195462<ref>PMID:16195462</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 2ar8" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Pseudomonas fluorescens]]
[[Category: Dong C]]
[[Category: Flecks S]]
[[Category: Haupt C]]
[[Category: Naismith JH]]
[[Category: Unversucht S]]
[[Category: Van Pee KH]]