View source for 6ikg


==Crystal structure of substrate-bound S9 peptidase (S514A mutant) from Deinococcus radiodurans==
<StructureSection load='6ikg' size='340' side='right'caption='[[6ikg]], [[Resolution|resolution]] 2.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6ikg]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Deinococcus_radiodurans Deinococcus radiodurans] and [https://en.wikipedia.org/wiki/Deinococcus_radiodurans_R1 Deinococcus radiodurans R1]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6IKG OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6IKG 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]] 2.3&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</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=6ikg FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6ikg OCA], [https://pdbe.org/6ikg PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6ikg RCSB], [https://www.ebi.ac.uk/pdbsum/6ikg PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6ikg ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q9RXY9_DEIRA Q9RXY9_DEIRA] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Serine peptidases of the prolyl oligopeptidase (POP) family are of substantial therapeutic importance because of their involvement in diseases such as diabetes, cancer, neurological diseases, and autoimmune disorders. Proper annotation and knowledge of substrate specificity mechanisms in this family are highly valuable. Although endopeptidase, dipeptidyl peptidase, tripeptidyl peptidase, and acylaminoacyl peptidase activities have been reported previously, here we report the first instance of carboxypeptidase activity in a POP family member. We determined the crystal structures of this carboxypeptidase, an S9C subfamily member from Deinococcus radiodurans, in its active and inactive states at 2.3-A resolution, providing an unprecedented view of assembly and disassembly of the active site mediated by an arginine residue. We observed that this residue is poised to bind substrate in the active structure and disrupts the catalytic triad in the inactive structure. The assembly of the active site is accompanied by the ordering of gating loops, which reduces the effective size of the oligomeric pore. This prevents the entry of larger peptides and constitutes a novel mechanism for substrate screening. Furthermore, we observed structural adaptations that enable its carboxypeptidase activity, with a unique loop and two arginine residues in the active site cavity orienting the peptide substrate for catalysis. Using these structural features, we identified homologs of this enzyme in the POP family and confirmed the presence of carboxypeptidase activity in one of them. In conclusion, we have identified a new type within POP enzymes that exhibits not only unique activity but also a novel substrate-screening mechanism.

Carboxypeptidase in prolyl oligopeptidase family: Unique enzyme activation and substrate-screening mechanisms.,Yadav P, Goyal VD, Gaur NK, Kumar A, Gokhale SM, Jamdar SN, Makde RD J Biol Chem. 2019 Jan 4;294(1):89-100. doi: 10.1074/jbc.RA118.004254. Epub 2018, Nov 8. PMID:30409909<ref>PMID:30409909</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6ikg" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Deinococcus radiodurans]]
[[Category: Deinococcus radiodurans R1]]
[[Category: Large Structures]]
[[Category: Goyal VD]]
[[Category: Kumar A]]
[[Category: Makde RD]]
[[Category: Yadav P]]