This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.

Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.

1np4

From Proteopedia

(Difference between revisions)

Jump to: navigation, search

Revision as of 09:26, 10 September 2015

CRYSTAL STRUCTURE OF NITROPHORIN 4 FROM RHODNIUS PROLIXUS

Structural highlights

1np4 is a 1 chain structure with sequence from Rhopr. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:	,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum

Function

[NP4_RHOPR] Heme-based protein that deliver nitric oxide gas (NO) to the victim while feeding, resulting in vasodilation and inhibition of platelet aggregation. Also bind tightly to histamine, which is released by the host to induce wound healing (By similarity).

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

BACKGROUND: Nitrophorins are nitric oxide (NO) transport proteins from the saliva of blood-feeding insects, which act as vasodilators and anti-platelet agents. Rhodnius prolixus, an insect that carries the trypanosome that causes Chagas' disease, releases four NO-loaded nitrophorins during blood feeding, whereupon the ligand is released into the bloodstream or surrounding tissue of the host. Histamine, a signaling molecule released by the host upon tissue damage, is tightly bound by the nitrophorins; this may facilitate the release of NO and reduce inflammation in the host. RESULTS: Recombinant nitrophorin 4 (NP4) was expressed in Escherichia coli, reconstituted with heme, and found to bind NO and histamine in a manner similar to that of the natural protein. The crystal structure of NP4 revealed a lipocalin-like eight-stranded beta barrel, with heme inserted into one end of the barrel. His59 ligates the proximal site on the heme, a solvent molecule (NH3) ligates the distal site, and three additional solvent molecules occupy the distal pocket. Buried in the protein interior are Glu55 and three solvent molecules. A detailed comparison with other lipocalins suggests that NP4 is closely related to the biliverdin-binding proteins from insects. CONCLUSIONS: The nitrophorins have a unique hemoprotein structure and are completely unlike the globins, the only other hemoproteins designed to transport dissolved gases. Compared with the recently described structure of NP1, the NP4 structure is considerably higher resolution, confirms the unusual placement of ionizable groups in the protein interior, and clarifies the solvent arrangement in the distal pocket. It also provides a striking example of structural homology where sequence homology is minimal.

The crystal structure of nitrophorin 4 at 1.5 A resolution: transport of nitric oxide by a lipocalin-based heme protein.,Andersen JF, Weichsel A, Balfour CA, Champagne DE, Montfort WR Structure. 1998 Oct 15;6(10):1315-27. PMID:9782054^[1]

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

References

↑ Andersen JF, Weichsel A, Balfour CA, Champagne DE, Montfort WR. The crystal structure of nitrophorin 4 at 1.5 A resolution: transport of nitric oxide by a lipocalin-based heme protein. Structure. 1998 Oct 15;6(10):1315-27. PMID:9782054

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

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1np4"

@@ Line 2: / Line 2: @@
 <StructureSection load='1np4' size='340' side='right' caption='[[1np4]], [[Resolution|resolution]] 1.50&Aring;' scene=''>
 == Structural highlights ==
-<table><tr><td colspan='2'>[[1np4]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Rhodnius_prolixus Rhodnius prolixus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NP4 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1NP4 FirstGlance]. <br>
+<table><tr><td colspan='2'>[[1np4]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Rhopr Rhopr]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NP4 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1NP4 FirstGlance]. <br>
 </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=NH3:AMMONIA'>NH3</scene></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=1np4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1np4 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1np4 RCSB], [http://www.ebi.ac.uk/pdbsum/1np4 PDBsum]</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=1np4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1np4 OCA], [http://pdbe.org/1np4 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1np4 RCSB], [http://www.ebi.ac.uk/pdbsum/1np4 PDBsum]</span></td></tr>
 </table>
 == Function ==
@@ Line 26: / Line 26: @@
 From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
 </div>
+<div class="pdbe-citations 1np4" style="background-color:#fffaf0;"></div>
 == References ==
 <references/>
 __TOC__
 </StructureSection>
-[[Category: Rhodnius prolixus]]
+[[Category: Rhopr]]
 [[Category: Andersen, J F]]
 [[Category: Balfour, C A]]

1np4

From Proteopedia

Revision as of 09:26, 10 September 2015

CRYSTAL STRUCTURE OF NITROPHORIN 4 FROM RHODNIUS PROLIXUS

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

Personal tools

Navigation

Search

Toolbox