View source for 5exv


==Crystal structure of heme binding protein HutX from Vibrio cholerae==
<StructureSection load='5exv' size='340' side='right'caption='[[5exv]], [[Resolution|resolution]] 2.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5exv]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Vibrio_cholerae Vibrio cholerae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5EXV OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5EXV 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]] 2.901&#8491;</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=5exv FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5exv OCA], [https://pdbe.org/5exv PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5exv RCSB], [https://www.ebi.ac.uk/pdbsum/5exv PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5exv ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/HUTX_VIBCH HUTX_VIBCH] Binds heme (PubMed:25664785, PubMed:26807477). Heme is transferred to the heme-degrading enzyme HutZ via a specific protein-protein interaction (PubMed:26807477).<ref>PMID:25664785</ref> <ref>PMID:26807477</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
HutZ is a cytoplasmic heme-binding protein from Vibrio cholerae. Although we have previously identified HutZ as a heme-degrading enzyme [Uchida, T., et al. (2012) Chem. Commun. 48, 6741-6743], the heme transport protein for HutZ remained unknown. To identify the heme transport protein for HutZ, we focused on the heme utilization operon, hutWXZ. To this end, we constructed an expression system for HutX in Escherichia coli and purified it to homogeneity. An absorption spectral analysis demonstrated that HutX binds heme with a 1:1 stoichiometry and a dissociation constant of 7.4 nM. The crystal structure of HutX displays a fold similar to that of the homologous protein, ChuX, from E. coli O157:H7. A structural comparison of HutX and ChuX, and resonance Raman spectra of heme-HutX, suggest that the axial ligand of the ferric heme is Tyr90. The heme bound to HutX is transferred to HutZ with biphasic dissociation kinetics of 8.3 x 10(-2) and 1.5 x 10(-2) s(-1), values distinctly larger than those for transfer from HutX to apomyoglobin. Surface plasmon resonance experiments confirmed that HutX interacts with HutZ with a dissociation constant of approximately 400 muM. These results suggest that heme is transferred from HutX to HutZ via a specific protein-protein interaction. Therefore, we can conclude that HutX is a cytoplasmic heme transport protein for HutZ.

Cytoplasmic Heme-Binding Protein (HutX) from Vibrio cholerae Is an Intracellular Heme Transport Protein for the Heme-Degrading Enzyme, HutZ.,Sekine Y, Tanzawa T, Tanaka Y, Ishimori K, Uchida T Biochemistry. 2016 Feb 16;55(6):884-93. doi: 10.1021/acs.biochem.5b01273. Epub, 2016 Feb 3. PMID:26807477<ref>PMID:26807477</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5exv" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Vibrio cholerae]]
[[Category: Sekine Y]]
[[Category: Tanaka Y]]
[[Category: Uchida T]]