View source for 1i5k


==STRUCTURE AND BINDING DETERMINANTS OF THE RECOMBINANT KRINGLE-2 DOMAIN OF HUMAN PLASMINOGEN TO AN INTERNAL PEPTIDE FROM A GROUP A STREPTOCOCCAL SURFACE PROTEIN==
<StructureSection load='1i5k' size='340' side='right'caption='[[1i5k]], [[Resolution|resolution]] 2.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1i5k]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [https://en.wikipedia.org/wiki/Streptococcus_pyogenes Streptococcus pyogenes]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1I5K OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1I5K 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]] 2.7&#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=1i5k FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1i5k OCA], [https://pdbe.org/1i5k PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1i5k RCSB], [https://www.ebi.ac.uk/pdbsum/1i5k PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1i5k ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/PLMN_HUMAN PLMN_HUMAN] Defects in PLG are the cause of plasminogen deficiency (PLGD) [MIM:[https://omim.org/entry/217090 217090]. PLGD is characterized by decreased serum plasminogen activity. Two forms of the disorder are distinguished: type 1 deficiency is additionally characterized by decreased plasminogen antigen levels and clinical symptoms, whereas type 2 deficiency, also known as dysplasminogenemia, is characterized by normal, or slightly reduced antigen levels, and absence of clinical manifestations. Plasminogen deficiency type 1 results in markedly impaired extracellular fibrinolysis and chronic mucosal pseudomembranous lesions due to subepithelial fibrin deposition and inflammation. The most common clinical manifestation of type 1 deficiency is ligneous conjunctivitis in which pseudomembranes formation on the palpebral surfaces of the eye progresses to white, yellow-white, or red thick masses with a wood-like consistency that replace the normal mucosa.<ref>PMID:1986355</ref> <ref>PMID:8392398</ref> <ref>PMID:6216475</ref> <ref>PMID:6238949</ref> <ref>PMID:1427790</ref> <ref>PMID:9242524</ref> <ref>PMID:9858247</ref> <ref>PMID:10233898</ref> 
== Function ==
[https://www.uniprot.org/uniprot/PLMN_HUMAN PLMN_HUMAN] Plasmin dissolves the fibrin of blood clots and acts as a proteolytic factor in a variety of other processes including embryonic development, tissue remodeling, tumor invasion, and inflammation. In ovulation, weakens the walls of the Graafian follicle. It activates the urokinase-type plasminogen activator, collagenases and several complement zymogens, such as C1 and C5. Cleavage of fibronectin and laminin leads to cell detachment and apoptosis. Also cleaves fibrin, thrombospondin and von Willebrand factor. Its role in tissue remodeling and tumor invasion may be modulated by CSPG4. Binds to cells.<ref>PMID:14699093</ref>   Angiostatin is an angiogenesis inhibitor that blocks neovascularization and growth of experimental primary and metastatic tumors in vivo.<ref>PMID:14699093</ref> 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/i5/1i5k_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1i5k ConSurf].
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== Publication Abstract from PubMed ==
The X-ray crystal structure of a complex of a modified recombinant kringle-2 domain of human plasminogen, K2Pg[C4G/E56D/L72Y] (mK2Pg), containing an upregulated lysine-binding site, bound to a functional 30 residue internal peptide (VEK-30) from an M-type protein of a group A Streptococcus surface protein, has been determined by molecular replacement methods using K4Pg as a model, and refined at 2.7 A resolution to a R-factor of 19.5 %. The X-ray crystal structure shows that VEK-30 exists as a nearly end-to-end alpha-helix in the complex with mK2Pg. The final structure also revealed that Arg17 and His18 of VEK-30 served as cationic loci for Asp54 and Asp56 of the consensus lysine-binding site of mK2Pg, while Glu20 of VEK-30 coordinates with Arg69 of the cationic binding site of mK2Pg. The hydrophobic ligand-binding pocket in mK2Pg, consisting primarily of Trp60 and Trp70, situated between the positive and negative centers of the lysine-binding site, is utilized in a novel manner in stabilizing the interaction with VEK-30 by forming a cation-pi-electron-mediated association with the positive side-chain of Arg17 of this peptide. Additional lysine-binding sites, as well as exosite electrostatic and hydrogen bonding interactions involving Glu9 and Lys14 of VEK-30, were observed in the structural model. The importance of these interactions were tested in solution by investigating the binding constants of synthetic variants of VEK-30 to mK2Pg, and it was found that, Lys14, Arg17, His18, and Glu20 of VEK-30 were the most critical amino acid binding determinants. With regard to the solution studies, circular dichroism analysis of the titration of VEK-30 with mK2Pg demonstrated that the peptidic alpha-helical structure increased substantially when bound to the kringle module, in agreement with the X-ray results.This investigation is the first to delineate structurally the mode of interaction of the lysine-binding site of a kringle with an internal pseudo-lysine residue of a peptide or protein that functionally interacts with a kringle module, and serves as a paradigm for this important class of interactions.

Structure and binding determinants of the recombinant kringle-2 domain of human plasminogen to an internal peptide from a group A Streptococcal surface protein.,Rios-Steiner JL, Schenone M, Mochalkin I, Tulinsky A, Castellino FJ J Mol Biol. 2001 May 11;308(4):705-19. PMID:11350170<ref>PMID:11350170</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Plasminogen 3D structures|Plasminogen 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Streptococcus pyogenes]]
[[Category: Castellino FJ]]
[[Category: Mochalkin I]]
[[Category: Rios-Steiner JL]]
[[Category: Schenone M]]
[[Category: Tulinsky A]]