View source for 3ep8


==Human AdoMetDC E178Q mutant complexed with S-Adenosylmethionine methyl ester and no putrescine bound==
<StructureSection load='3ep8' size='340' side='right'caption='[[3ep8]], [[Resolution|resolution]] 1.97&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3ep8]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3EP8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3EP8 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]] 1.97&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=PYR:PYRUVIC+ACID'>PYR</scene>, <scene name='pdbligand=SMM:S-ADENOSYLMETHIONINE+METHYL+ESTER'>SMM</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=3ep8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3ep8 OCA], [https://pdbe.org/3ep8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3ep8 RCSB], [https://www.ebi.ac.uk/pdbsum/3ep8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3ep8 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/DCAM_HUMAN DCAM_HUMAN] 
== 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/ep/3ep8_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=3ep8 ConSurf].
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<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Putrescine (1,4-diaminobutane) activates the autoprocessing and decarboxylation reactions of human S-adenosylmethionine decarboxylase (AdoMetDC), a critical enzyme in the polyamine biosynthetic pathway. In human AdoMetDC, putrescine binds in a buried pocket containing acidic residues Asp174, Glu178, and Glu256. The pocket is away from the active site but near the dimer interface; however, a series of hydrophilic residues connect the putrescine binding site and the active site. Mutation of these acidic residues modulates the effects of putrescine. D174N, E178Q, and E256Q mutants were expressed and dialyzed to remove putrescine and studied biochemically using X-ray crystallography, UV-CD spectroscopy, analytical ultracentrifugation, and ITC binding studies. The results show that the binding of putrescine to the wild type dimeric protein is cooperative. The D174N mutant does not bind putrescine, and the E178Q and E256Q mutants bind putrescine weakly with no cooperativity. The crystal structure of the mutants with and without putrescine and their complexes with S-adenosylmethionine methyl ester were obtained. Binding of putrescine results in a reorganization of four aromatic residues (Phe285, Phe315, Tyr318, and Phe320) and a conformational change in the loop 312-320. The loop shields putrescine from the external solvent, enhancing its electrostatic and hydrogen bonding effects. The E256Q mutant with putrescine added shows an alternate conformation of His243, Glu11, Lys80, and Ser229, the residues that link the active site and the putrescine binding site, suggesting that putrescine activates the enzyme through electrostatic effects and acts as a switch to correctly orient key catalytic residues.

Structural basis for putrescine activation of human S-adenosylmethionine decarboxylase.,Bale S, Lopez MM, Makhatadze GI, Fang Q, Pegg AE, Ealick SE Biochemistry. 2008 Dec 16;47(50):13404-17. PMID:19053272<ref>PMID:19053272</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 3ep8" style="background-color:#fffaf0;"></div>

==See Also==
*[[SAM decarboxylase|SAM decarboxylase]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Bale S]]
[[Category: Ealick SE]]
[[Category: Fang Q]]
[[Category: Lopez MM]]
[[Category: Makhatadze GI]]
[[Category: Pegg AE]]