View source for 3anx


==Crystal structure of triamine/agmatine aminopropyltransferase (SPEE) from thermus thermophilus, complexed with MTA==
<StructureSection load='3anx' size='340' side='right'caption='[[3anx]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3anx]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Thet8 Thet8]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3ANX OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3ANX FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MTA:5-DEOXY-5-METHYLTHIOADENOSINE'>MTA</scene></td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Spermidine_synthase Spermidine synthase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.5.1.16 2.5.1.16] </span></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=3anx FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3anx OCA], [https://pdbe.org/3anx PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3anx RCSB], [https://www.ebi.ac.uk/pdbsum/3anx PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3anx ProSAT]</span></td></tr>
</table>
== Function ==
[[https://www.uniprot.org/uniprot/SPEE_THET8 SPEE_THET8]] Catalyzes the production of spermidine from putrescine and decarboxylated S-adenosylmethionine (dcSAM), which serves as an aminopropyl donor. Has broad substrate specificity. Is also active with agmatine and norspermidine. Has lower activity with homospermidine, mitsubishine and thermine.<ref>PMID:21458463</ref>  
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
To maintain functional conformations of DNA and RNA in high-temperature environments, an extremely thermophilic bacterium, Thermus thermophilus, employs a unique polyamine biosynthetic pathway and produces more than 16 types of polyamines. In the thermophile genome, only one spermidine synthase homolog (SpeE) was found and it was shown to be a key enzyme in the pathway. The catalytic assay of the purified enzyme revealed that it utilizes triamines (norspermidine and spermidine) and agmatine as acceptors in its aminopropyl transfer reaction; therefore, the enzyme was denoted as a triamine/agmatine aminopropyltransferase (TAAPT). We determined the crystal structures of the enzyme complexed with and without the aminopropyl group donor S-adenosylmethionine. Despite sequence and structural similarity with spermidine synthases from other organisms, a novel C-terminal beta-sheet and differences in the catalytic site were observed. The C-terminal module interacts with the gatekeeping loop and fixes the open conformation of the loop to recognize larger polyamine substrates such as agmatine and spermidine. Additional computational docking studies suggest that the structural differences of the catalytic site also contribute to recognition of the aminopropyl/aminobutyl or guanidium moiety of the substrates of TAAPT. These results explain in part the extraordinarily diverse polyamine spectrum found in T. thermophilus.

Crystal structures and enzymatic properties of a triamine/agmatine aminopropyltransferase from Thermus thermophilus.,Ohnuma M, Ganbe T, Terui Y, Niitsu M, Sato T, Tanaka N, Tamakoshi M, Samejima K, Kumasaka T, Oshima T J Mol Biol. 2011 May 20;408(5):971-86. Epub 2011 Mar 31. PMID:21458463<ref>PMID:21458463</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3anx" style="background-color:#fffaf0;"></div>

==See Also==
*[[Spermidine synthase 3D structures|Spermidine synthase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Spermidine synthase]]
[[Category: Thet8]]
[[Category: Ganbe, T]]
[[Category: Kumasaka, T]]
[[Category: Ohnuma, M]]
[[Category: Oshima, T]]
[[Category: Sato, T]]
[[Category: Tanaka, N]]
[[Category: Polyamine]]
[[Category: Spee]]
[[Category: Spermidine biosynthesis]]
[[Category: Spermine synthase]]
[[Category: Transferase-transferase inhibitor complex]]