5zlg

From Proteopedia

(Difference between revisions)

Revision as of 06:46, 31 October 2018

Human duodenal cytochrome b (Dcytb) in zinc ion and ascorbate bound form

Structural highlights

5zlg is a 1 chain structure. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:	, ,
Related:	5zle
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[CYBR1_HUMAN] Ferric-chelate reductase that reduces Fe(3+) to Fe(2+). Present at the brush border of duodenal enterocytes where it probably reduces dietary Fe(3+) thereby facilitating its transport into the mucosal cells. Uses ascorbate as electron donor. May be involved in extracellular ascorbate recycling in erythrocyte membranes. May also act as a ferrireductase in airway epithelial cells.^[1] ^[2] ^[3] ^[4]

Publication Abstract from PubMed

Dietary iron absorption is regulated by duodenal cytochrome b (Dcytb), an integral membrane protein that catalyzes reduction of nonheme Fe(3+) by electron transfer from ascorbate across the membrane. This step is essential to enable iron uptake by the divalent metal transporter. Here we report the crystallographic structures of human Dcytb and its complex with ascorbate and Zn(2+). Each monomer of the homodimeric protein possesses cytoplasmic and apical heme groups, as well as cytoplasmic and apical ascorbate-binding sites located adjacent to each heme. Zn(2+) coordinates to two hydroxyl groups of the apical ascorbate and to a histidine residue. Biochemical analysis indicates that Fe(3+) competes with Zn(2+) for this binding site. These results provide a structural basis for the mechanism by which Fe(3+) uptake is promoted by reducing agents and should facilitate structure-based development of improved agents for absorption of orally administered iron.

Structural basis for promotion of duodenal iron absorption by enteric ferric reductase with ascorbate.,Ganasen M, Togashi H, Takeda H, Asakura H, Tosha T, Yamashita K, Hirata K, Nariai Y, Urano T, Yuan X, Hamza I, Mauk AG, Shiro Y, Sugimoto H, Sawai H Commun Biol. 2018 Aug 17;1:120. doi: 10.1038/s42003-018-0121-8. eCollection 2018. PMID:30272000^[5]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Zaahl MG, Merryweather-Clarke AT, Kotze MJ, van der Merwe S, Warnich L, Robson KJ. Gene symbol: DCYTB/CYBRD1. Disease: primary iron overload. Hum Genet. 2005 Dec;118(3-4):548-9. PMID:16521311
↑ Zaahl MG, Merryweather-Clarke AT, Kotze MJ, van der Merwe S, Warnich L, Robson KJ. Gene symbol: DCYTB/CYBRD1. Disease: primary iron overload. Hum Genet. 2005 Dec;118(3-4):549. PMID:16521312
↑ Su D, May JM, Koury MJ, Asard H. Human erythrocyte membranes contain a cytochrome b561 that may be involved in extracellular ascorbate recycling. J Biol Chem. 2006 Dec 29;281(52):39852-9. Epub 2006 Oct 26. PMID:17068337 doi:http://dx.doi.org/M606543200
↑ Constantine CC, Anderson GJ, Vulpe CD, McLaren CE, Bahlo M, Yeap HL, Gertig DM, Osborne NJ, Bertalli NA, Beckman KB, Chen V, Matak P, McKie AT, Delatycki MB, Olynyk JK, English DR, Southey MC, Giles GG, Hopper JL, Allen KJ, Gurrin LC. A novel association between a SNP in CYBRD1 and serum ferritin levels in a cohort study of HFE hereditary haemochromatosis. Br J Haematol. 2009 Oct;147(1):140-9. doi: 10.1111/j.1365-2141.2009.07843.x. Epub, 2009 Aug 10. PMID:19673882 doi:http://dx.doi.org/10.1111/j.1365-2141.2009.07843.x
↑ Ganasen M, Togashi H, Takeda H, Asakura H, Tosha T, Yamashita K, Hirata K, Nariai Y, Urano T, Yuan X, Hamza I, Mauk AG, Shiro Y, Sugimoto H, Sawai H. Structural basis for promotion of duodenal iron absorption by enteric ferric reductase with ascorbate. Commun Biol. 2018 Aug 17;1:120. doi: 10.1038/s42003-018-0121-8. eCollection 2018. PMID:30272000 doi:http://dx.doi.org/10.1038/s42003-018-0121-8

1 Structural highlights
2 Function
3 Publication Abstract from PubMed
4 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/5zlg"

@@ Line 1: / Line 1: @@
-'''Unreleased structure'''
-The entry 5zlg is ON HOLD  until Paper Publication
+==Human duodenal cytochrome b (Dcytb) in zinc ion and ascorbate bound form==
+<StructureSection load='5zlg' size='340' side='right' caption='[[5zlg]], [[Resolution|resolution]] 2.80&Aring;' scene=''>
+== Structural highlights ==
+<table><tr><td colspan='2'>[[5zlg]] is a 1 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5ZLG OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5ZLG FirstGlance]. <br>
+</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ASC:ASCORBIC+ACID'>ASC</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr>
+<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[5zle|5zle]]</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=5zlg FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5zlg OCA], [http://pdbe.org/5zlg PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5zlg RCSB], [http://www.ebi.ac.uk/pdbsum/5zlg PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5zlg ProSAT]</span></td></tr>
+</table>
+== Function ==
+[[http://www.uniprot.org/uniprot/CYBR1_HUMAN CYBR1_HUMAN]] Ferric-chelate reductase that reduces Fe(3+) to Fe(2+). Present at the brush border of duodenal enterocytes where it probably reduces dietary Fe(3+) thereby facilitating its transport into the mucosal cells. Uses ascorbate as electron donor. May be involved in extracellular ascorbate recycling in erythrocyte membranes. May also act as a ferrireductase in airway epithelial cells.<ref>PMID:16521311</ref> <ref>PMID:16521312</ref> <ref>PMID:17068337</ref> <ref>PMID:19673882</ref>
+<div style="background-color:#fffaf0;">
+== Publication Abstract from PubMed ==
+Dietary iron absorption is regulated by duodenal cytochrome b (Dcytb), an integral membrane protein that catalyzes reduction of nonheme Fe(3+) by electron transfer from ascorbate across the membrane. This step is essential to enable iron uptake by the divalent metal transporter. Here we report the crystallographic structures of human Dcytb and its complex with ascorbate and Zn(2+). Each monomer of the homodimeric protein possesses cytoplasmic and apical heme groups, as well as cytoplasmic and apical ascorbate-binding sites located adjacent to each heme. Zn(2+) coordinates to two hydroxyl groups of the apical ascorbate and to a histidine residue. Biochemical analysis indicates that Fe(3+) competes with Zn(2+) for this binding site. These results provide a structural basis for the mechanism by which Fe(3+) uptake is promoted by reducing agents and should facilitate structure-based development of improved agents for absorption of orally administered iron.
-Authors: Ganasen, M., Togashi, H., Mauk, G.A., Shiro, Y., Sawai, H., Sugimoto, H.
+Structural basis for promotion of duodenal iron absorption by enteric ferric reductase with ascorbate.,Ganasen M, Togashi H, Takeda H, Asakura H, Tosha T, Yamashita K, Hirata K, Nariai Y, Urano T, Yuan X, Hamza I, Mauk AG, Shiro Y, Sugimoto H, Sawai H Commun Biol. 2018 Aug 17;1:120. doi: 10.1038/s42003-018-0121-8. eCollection 2018. PMID:30272000<ref>PMID:30272000</ref>
-Description: Human duodenal cytochrome b (Dcytb) in zinc ion and ascorbate bound form
+From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
-[[Category: Unreleased Structures]]
+</div>
-[[Category: Shiro, Y]]
+<div class="pdbe-citations 5zlg" style="background-color:#fffaf0;"></div>
+== References ==
+<references/>
+__TOC__
+</StructureSection>
 [[Category: Ganasen, M]]
-[[Category: Sugimoto, H]]
+[[Category: Mauk, G A]]
 [[Category: Sawai, H]]
-[[Category: Mauk, G.A]]
+[[Category: Shiro, Y]]
+[[Category: Sugimoto, H]]
 [[Category: Togashi, H]]
+[[Category: Electron transport]]
+[[Category: Oxidoreductase]]

5zlg

From Proteopedia

Revision as of 06:46, 31 October 2018

Human duodenal cytochrome b (Dcytb) in zinc ion and ascorbate bound form

Structural highlights

Function

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

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