1ntf

<StructureSection load='1ntf' size='340' side='right' caption='[[1ntf]], [[Resolution|resolution]] 1.80&Aring;' scene=''>

<table><tr><td colspan='2'>[[1ntf]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Acanthia_lectularia Acanthia lectularia]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NTF OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1NTF 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></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=1ntf FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ntf OCA], [http://pdbe.org/1ntf PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1ntf RCSB], [http://www.ebi.ac.uk/pdbsum/1ntf PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1ntf ProSAT]</span></td></tr>

<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/nt/1ntf_consurf.spt"</scriptWhenChecked>

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== Publication Abstract from PubMed ==

Certain bloodsucking insects deliver nitric oxide (NO) while feeding, to induce vasodilation and inhibit blood coagulation. We have expressed, characterized, and determined the crystal structure of the Cimex lectularius (bedbug) nitrophorin, the protein responsible for NO storage and delivery, to understand how the insect successfully handles this reactive molecule. Surprisingly, NO binds not only to the ferric nitrophorin heme, but it can also be stored as an S-nitroso (SNO) conjugate of the proximal heme cysteine (Cys-60) when present at higher concentrations. EPR- and UV-visible spectroscopies, and a crystallographic structure determination to 1.75-A resolution, reveal SNO formation to proceed with reduction of the heme iron, yielding an Fe-NO complex. Stopped-flow kinetic measurements indicate that an ordered reaction mechanism takes place: initial NO binding occurs at the ferric heme and is followed by heme reduction, Cys-60 release from the heme iron, and SNO formation. Release of NO occurs through a reversal of these steps. These data provide, to our knowledge, the first view of reversible metal-assisted SNO formation in a protein and suggest a mechanism for its role in NO release from ferrous heme. This mechanism and Cimex nitrophorin structure are completely unlike those of the nitrophorins from Rhodnius prolixus, where NO protection is provided by a large conformational change that buries the heme nitrosyl complex, highlighting the remarkable evolution of proteins that assist insects in bloodfeeding.

 

<div class="pdbe-citations 1ntf" style="background-color:#fffaf0;"></div>

[[Category: Acanthia lectularia]]

[[Category: Andersen, J F]]

[[Category: Maes, E M]]

[[Category: Montfort, W R]]

[[Category: Valenzuela, J G]]

[[Category: Walker, F A]]

[[Category: Weichsel, A]]

[[Category: Transport protein]]