View source for 2vck


==Structure of Phycoerythrobilin Synthase PebS from the Cyanophage P-SSM2 in Complex with the bound Substrate Biliverdin IXa==
<StructureSection load='2vck' size='340' side='right'caption='[[2vck]], [[Resolution|resolution]] 1.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2vck]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Prochlorococcus_phage_P-SSM2 Prochlorococcus phage P-SSM2]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2VCK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2VCK 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]] 1.8&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BLA:BILIVERDINE+IX+ALPHA'>BLA</scene>, <scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</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=2vck FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2vck OCA], [https://pdbe.org/2vck PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2vck RCSB], [https://www.ebi.ac.uk/pdbsum/2vck PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2vck ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/PEBS_BPPRM PEBS_BPPRM] Plays a role in phycoerythrobilin biosynthesis, the red pigment chromophore photosynthetically active biliproteins of the host cyanobacteria. Uses a four-electron reduction to carry out the reactions catalyzed by two enzymes (EC 1.3.7.2 and EC 1.3.7.3) in host.
== 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/vc/2vck_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=2vck ConSurf].
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== Publication Abstract from PubMed ==
The reddish purple open chain tetrapyrrole pigment phycoerythrobilin (PEB; A(lambdamax) approximately 550 nm) is an essential chromophore of the light-harvesting phycobiliproteins of most cyanobacteria, red algae, and cryptomonads. The enzyme phycoerythrobilin synthase (PebS), recently discovered in a marine virus infecting oceanic cyanobacteria of the genus Prochlorococcus (cyanophage PSSM-2), is a new member of the ferredoxin-dependent bilin reductase (FDBR) family. In a formal four-electron reduction, the substrate biliverdin IXalpha is reduced to yield 3Z-PEB, a reaction that commonly requires the action of two individual FDBRs. The first reaction catalyzed by PebS is the reduction of the 15,16-methine bridge of the biliverdin IXalpha tetrapyrrole system. This reaction is exclusive to PEB biosynthetic enzymes. The second reduction site is the A-ring 2,3,3(1),3(2)-diene system, the most common target of FDBRs. Here, we present the first crystal structures of a PEB biosynthetic enzyme. Structures of the substrate complex were solved at 1.8- and 2.1-A resolution and of the substrate-free form at 1.55-A resolution. The overall folding revealed an alpha/beta/alpha-sandwich with similarity to the structure of phycocyanobilin:ferredoxin oxidoreductase (PcyA). The substrate-binding site is located between the central beta-sheet and C-terminal alpha-helices. Eight refined molecules with bound substrate, from two different crystal forms, revealed a high flexibility of the substrate-binding pocket. The substrate was found to be either in a planar porphyrin-like conformation or in a helical conformation and is coordinated by a conserved aspartate/asparagine pair from the beta-sheet side. From the alpha-helix side, a conserved highly flexible aspartate/proline pair is involved in substrate binding and presumably catalysis.

Phycoerythrobilin synthase (PebS) of a marine virus. Crystal structures of the biliverdin complex and the substrate-free form.,Dammeyer T, Hofmann E, Frankenberg-Dinkel N J Biol Chem. 2008 Oct 10;283(41):27547-54. Epub 2008 Jul 28. PMID:18662988<ref>PMID:18662988</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Prochlorococcus phage P-SSM2]]
[[Category: Dammeyer T]]
[[Category: Frankenberg-Dinkel N]]
[[Category: Hofmann E]]