View source for 4dik


==Flavo Di-iron protein H90A mutant from Thermotoga maritima==
<StructureSection load='4dik' size='340' side='right'caption='[[4dik]], [[Resolution|resolution]] 1.75&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4dik]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Thermotoga_maritima Thermotoga maritima]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4DIK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4DIK 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]] 1.75&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=FEO:MU-OXO-DIIRON'>FEO</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=4dik FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4dik OCA], [https://pdbe.org/4dik PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4dik RCSB], [https://www.ebi.ac.uk/pdbsum/4dik PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4dik ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q9WZL4_THEMA Q9WZL4_THEMA] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Flavo-diiron proteins (FDPs) contain non-heme diiron and proximal flavin mononucleotide (FMN) active sites and function as terminal components of a nitric oxide reductase (NOR) and/or a four-electron dioxygen reductase (O(2)R). While most FDPs show similar structural, spectroscopic, and redox properties, O(2)R and NOR activities vary significantly among FDPs. A potential source of this variability is the iron ligation status of a conserved His residue that provides an iron ligand in all known FDP structures but one, where this His residue is rotated away from iron and replaced by a solvent ligand. In order to test the effect of this His ligation status, we changed this ligating His residue (H90) in Thermotoga maritima (Tm) FDP to either Asn or Ala. The wild-type Tm FDP shows significantly higher O(2)R than NOR activity. Single crystal X-ray crystallography revealed a remarkably conserved diiron site structure in the H90N and -A variants, differing mainly by either Asn or solvent coordination, respectively, in place of H90. The steady-state activities were minimally affected by the H90 substitutions, remaining significantly higher for O(2)R versus NOR. The pre-steady-state kinetics of the fully reduced FDP with O(2) were also minimally affected by the H90 substitutions. The results indicate that the coordination status of this His ligand does not significantly modulate the O(2)R or NOR activities, and that FDPs can retain these activities when the individual iron centers are differentiated by His ligand substitution. This differentiation may have implications for the O(2)R and NOR mechanisms of FDPs.

Histidine ligand variants of a flavo-diiron protein: effects on structure and activities.,Fang H, Caranto JD, Mendoza R, Taylor AB, Hart PJ, Kurtz DM Jr J Biol Inorg Chem. 2012 Sep 19. PMID:22990880<ref>PMID:22990880</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4dik" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Thermotoga maritima]]
[[Category: Caranto JD]]
[[Category: Fang H]]
[[Category: Hart PJ]]
[[Category: Kurtz Jr DM]]
[[Category: Taylor AB]]