2xx0: Difference between revisions

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-[[Image:2xx0.jpg|left|200px]]
-<!--
+==STRUCTURE OF THE N90S-H254F MUTANT OF NITRITE REDUCTASE FROM ALCALIGENES XYLOSOXIDANS==
-The line below this paragraph, containing "STRUCTURE_2xx0", creates the "Structure Box" on the page.
+<StructureSection load='2xx0' size='340' side='right'caption='[[2xx0]], [[Resolution|resolution]] 1.46&Aring;' scene=''>
-You may change the PDB parameter (which sets the PDB file loaded into the applet)
+== Structural highlights ==
-or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
+<table><tr><td colspan='2'>[[2xx0]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Achromobacter_xylosoxidans Achromobacter xylosoxidans]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2XX0 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2XX0 FirstGlance]. <br>
-or leave the SCENE parameter empty for the default display.
+</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.46&#8491;</td></tr>
--->
+<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CU:COPPER+(II)+ION'>CU</scene>, <scene name='pdbligand=MES:2-(N-MORPHOLINO)-ETHANESULFONIC+ACID'>MES</scene>, <scene name='pdbligand=PG4:TETRAETHYLENE+GLYCOL'>PG4</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr>
-{{STRUCTURE_2xx0|  PDB=2xx0  |  SCENE=  }}
+<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2xx0 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2xx0 OCA], [https://pdbe.org/2xx0 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2xx0 RCSB], [https://www.ebi.ac.uk/pdbsum/2xx0 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2xx0 ProSAT]</span></td></tr>
+</table>
+== Function ==
+[https://www.uniprot.org/uniprot/O68601_ALCXX O68601_ALCXX]
+<div style="background-color:#fffaf0;">
+== Publication Abstract from PubMed ==
+We demonstrated recently that two protons are involved in reduction of nitrite to nitric oxide through a proton-coupled electron transfer (ET) reaction catalyzed by the blue Cu-dependent nitrite reductase (Cu NiR) of Alcaligenes xylosoxidans (AxNiR). Here, the functionality of two putative proton channels, one involving Asn90 and the other His254, is studied using single (N90S, H254F) and double (N90S-H254F) mutants. All mutants studied are active, indicating that protons are still able to reach the active site. The H254F mutation has no effect on the catalytic activity, while the N90S mutation results in approximately 70% decrease in activity. Laser flash-photolysis experiments show that in H254F and wild-type enzyme electrons enter at the level of the T1Cu and then redistribute between the two Cu sites. Complete ET from T1Cu to T2Cu occurs only when nitrite binds at the T2Cu site. This indicates that substrate binding to T2Cu promotes ET from T1Cu, suggesting that the enzyme operates an ordered mechanism. In fact, in the N90S and N90S-H254F variants, where the T1Cu site redox potential is elevated by approximately 60 mV, inter-Cu ET is only observed in the presence of nitrite. From these results it is evident that the Asn90 channel is the main proton channel in AxNiR, though protons can still reach the active site if this channel is disrupted. Crystallographic structures provide a clear structural rationale for these observations, including restoration of the proton delivery via a significant movement of the loop connecting the T1Cu ligands Cys130 and His139 that occurs on binding of nitrite. Notably, a role for this loop in facilitating interaction of cytochrome c(551) with Cu NiR has been suggested previously based on a crystal structure of the binary complex.
-===STRUCTURE OF THE N90S-H254F MUTANT OF NITRITE REDUCTASE FROM ALCALIGENES XYLOSOXIDANS===
+Proton-Coupled Electron Transfer in the Catalytic Cycle of Alcaligenes xylosoxidans Copper-Dependent Nitrite Reductase.,Leferink NG, Han C, Antonyuk SV, Heyes DJ, Rigby SE, Hough MA, Eady RR, Scrutton NS, Hasnain SS Biochemistry. 2011 May 17;50(19):4121-31. Epub 2011 Apr 19. PMID:21469743<ref>PMID:21469743</ref>
+From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
+</div>
+<div class="pdbe-citations 2xx0" style="background-color:#fffaf0;"></div>
-<!--
+==See Also==
-The line below this paragraph, {{ABSTRACT_PUBMED_21469743}}, adds the Publication Abstract to the page
+*[[Nitrite reductase 3D structures|Nitrite reductase 3D structures]]
-(as it appears on PubMed at http://www.pubmed.gov), where 21469743 is the PubMed ID number.
+== References ==
--->
+<references/>
-{{ABSTRACT_PUBMED_21469743}}
+__TOC__
+</StructureSection>
-==About this Structure==
-[[2xx0]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Achromobacter_xylosoxidans Achromobacter xylosoxidans]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2XX0 OCA].
-==Reference==
-<ref group="xtra">PMID:021469743</ref><references group="xtra"/>
 [[Category: Achromobacter xylosoxidans]]
-[[Category: Antonyuk, S V.]]
+[[Category: Large Structures]]
-[[Category: Eady, R R.]]
+[[Category: Antonyuk SV]]
-[[Category: Han, C.]]
+[[Category: Eady RR]]
-[[Category: Hasnain, S S.]]
+[[Category: Han C]]
-[[Category: Heyes, D J.]]
+[[Category: Hasnain SS]]
-[[Category: Hough, M A.]]
+[[Category: Heyes DJ]]
-[[Category: Leferink, N G.H.]]
+[[Category: Hough MA]]
-[[Category: Rigby, S E.J.]]
+[[Category: Leferink NGH]]
-[[Category: Scrutton, N S.]]
+[[Category: Rigby SEJ]]
+[[Category: Scrutton NS]]