View source for 4xqg


==Crystal Structure of the Homospermidine Synthase (HSS) variant E237Q from Blastochloris viridis in Complex with NAD.==
<StructureSection load='4xqg' size='340' side='right'caption='[[4xqg]], [[Resolution|resolution]] 1.42&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4xqg]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Blastochloris_viridis Blastochloris viridis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4XQG OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4XQG 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]] 1.417&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=1PS:3-PYRIDINIUM-1-YLPROPANE-1-SULFONATE'>1PS</scene>, <scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=AG2:AGMATINE'>AG2</scene>, <scene name='pdbligand=NAD:NICOTINAMIDE-ADENINE-DINUCLEOTIDE'>NAD</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=4xqg FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4xqg OCA], [https://pdbe.org/4xqg PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4xqg RCSB], [https://www.ebi.ac.uk/pdbsum/4xqg PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4xqg ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/HSS_BLAVI HSS_BLAVI] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The highly conserved bacterial homospermidine synthase (HSS) is a key enzyme of the polyamine metabolism of many proteobacteria including pathogenic strains such as Legionella pneumophila and Pseudomonas aeruginosa; The unique usage of NAD(H) as a prosthetic group is a common feature of bacterial HSS, eukaryotic HSS and deoxyhypusine synthase (DHS). The structure of the bacterial enzyme does not possess a lysine residue in the active center and thus does not form an enzyme-substrate Schiff base intermediate as observed for the DHS. In contrast to the DHS the active site is not formed by the interface of two subunits but resides within one subunit of the bacterial HSS. Crystal structures of Blastochloris viridis HSS (BvHSS) reveal two distinct substrate binding sites, one of which is highly specific for putrescine. BvHSS features a side pocket in the direct vicinity of the active site formed by conserved amino acids and a potential substrate discrimination, guiding, and sensing mechanism. The proposed reaction steps for the catalysis of BvHSS emphasize cation-pi interaction through a conserved Trp residue as a key stabilizer of high energetic transition states.

Comprehensive Structural Characterization of the Bacterial Homospermidine Synthase-an Essential Enzyme of the Polyamine Metabolism.,Krossa S, Faust A, Ober D, Scheidig AJ Sci Rep. 2016 Jan 18;6:19501. doi: 10.1038/srep19501. PMID:26776105<ref>PMID:26776105</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4xqg" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Blastochloris viridis]]
[[Category: Large Structures]]
[[Category: Krossa S]]