View source for 6qpt


==Crystal structure of nitrite bound synthetic core domain of nitrite reductase from Ralstonia pickettii (residues 1-331)==
<StructureSection load='6qpt' size='340' side='right'caption='[[6qpt]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6qpt]] is a 6 chain structure with sequence from [http://en.wikipedia.org/wiki/Ralstonia_pickettii Ralstonia pickettii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6QPT OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6QPT FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CU:COPPER+(II)+ION'>CU</scene>, <scene name='pdbligand=NO2:NITRITE+ION'>NO2</scene>, <scene name='pdbligand=PG4:TETRAETHYLENE+GLYCOL'>PG4</scene></td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Nitrite_reductase_(NO-forming) Nitrite reductase (NO-forming)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.7.2.1 1.7.2.1] </span></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6qpt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6qpt OCA], [http://pdbe.org/6qpt PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6qpt RCSB], [http://www.ebi.ac.uk/pdbsum/6qpt PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6qpt ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
It is generally assumed that tethering enhances rates of electron harvesting and delivery to active sites in multidomain enzymes by proximity and sampling mechanisms. Here, we explore this idea in a tethered 3-domain, trimeric copper-containing nitrite reductase. By reverse engineering, we find that tethering does not enhance the rate of electron delivery from its pendant cytochrome c to the catalytic copper-containing core. Using a linker that harbors a gatekeeper tyrosine in a nitrite access channel, the tethered haem domain enables catalysis by other mechanisms. Tethering communicates the redox state of the haem to the distant T2Cu center that helps initiate substrate binding for catalysis. It also tunes copper reduction potentials, suppresses reductive enzyme inactivation, enhances enzyme affinity for substrate, and promotes intercopper electron transfer. Tethering has multiple unanticipated beneficial roles, the combination of which fine-tunes function beyond simplistic mechanisms expected from proximity and restrictive sampling models.

Unexpected Roles of a Tether Harboring a Tyrosine Gatekeeper Residue in Modular Nitrite Reductase Catalysis.,Hedison TM, Shenoy RT, Iorgu AI, Heyes DJ, Fisher K, Wright GSA, Hay S, Eady RR, Antonyuk SV, Hasnain SS, Scrutton NS ACS Catal. 2019 Jul 5;9(7):6087-6099. doi: 10.1021/acscatal.9b01266. Epub 2019, May 29. PMID:32051772<ref>PMID:32051772</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6qpt" style="background-color:#fffaf0;"></div>

==See Also==
*[[Nitrite reductase 3D structures|Nitrite reductase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Ralstonia pickettii]]
[[Category: Antonyuk, S V]]
[[Category: Eady, R R]]
[[Category: Hasnain, S S]]
[[Category: Hedison, T M]]
[[Category: Scrutton, N S]]
[[Category: Inter-copper electron transfer]]
[[Category: Metal binding protein]]
[[Category: Nitrite reductase]]
[[Category: Synthetic core domain]]