View source for 1psn


==THE CRYSTAL STRUCTURE OF HUMAN PEPSIN AND ITS COMPLEX WITH PEPSTATIN==
<StructureSection load='1psn' size='340' side='right'caption='[[1psn]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1psn]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1PSN OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1PSN 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]] 2.2&#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=1psn FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1psn OCA], [https://pdbe.org/1psn PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1psn RCSB], [https://www.ebi.ac.uk/pdbsum/1psn PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1psn ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/PEPA4_HUMAN PEPA4_HUMAN] Shows particularly broad specificity; although bonds involving phenylalanine and leucine are preferred, many others are also cleaved to some extent.
== 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/ps/1psn_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=1psn ConSurf].
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== Publication Abstract from PubMed ==
The three-dimensional crystal structure of human pepsin and that of its complex with pepstatin have been solved by X-ray crystallographic methods. The native pepsin structure has been refined with data collected to 2.2 A resolution to an R-factor of 19.7%. The pepsin:pepstatin structure has been refined with data to 2.0 A resolution to an R-factor of 18.5%. The hydrogen bonding interactions and the conformation adopted by pepstatin are very similar to those found in complexes of pepstatin with other aspartic proteinases. The enzyme undergoes a conformational change upon inhibitor binding to enclose the inhibitor more tightly. The analysis of the binding sites indicates that they form an extended tube without distinct binding pockets. By comparing the residues on the binding surface with those of the other human aspartic proteinases, it has been possible to rationalize some of the experimental data concerning the different specificities. At the S1 site, valine at position 120 in renin instead of isoleucine, as in the other enzymes, allows for binding of larger hydrophobic residues. The possibility of multiple conformations for the P2 residue makes the analysis of the S2 site difficult. However, it is possible to see that the specific interactions that renin makes with histidine at P2 would not be possible in the case of the other enzymes. At the S3 site, the smaller volume that is accessible in pepsin compared to the other enzymes is consistent with its preference for smaller residues at the P3 position.

Crystal structure of human pepsin and its complex with pepstatin.,Fujinaga M, Chernaia MM, Tarasova NI, Mosimann SC, James MN Protein Sci. 1995 May;4(5):960-72. PMID:7663352<ref>PMID:7663352</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Pepsin|Pepsin]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Chernaia MM]]
[[Category: Fujinaga M]]
[[Category: James MNG]]
[[Category: Mosimann SC]]
[[Category: Tarasova N]]