View source for 2psg


==REFINED STRUCTURE OF PORCINE PEPSINOGEN AT 1.8 ANGSTROMS RESOLUTION==
<StructureSection load='2psg' size='340' side='right'caption='[[2psg]], [[Resolution|resolution]] 1.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2psg]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Sus_scrofa Sus scrofa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2PSG OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2PSG 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]] 1.8&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=SEP:PHOSPHOSERINE'>SEP</scene></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=2psg FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2psg OCA], [https://pdbe.org/2psg PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2psg RCSB], [https://www.ebi.ac.uk/pdbsum/2psg PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2psg ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/PEPA_PIG PEPA_PIG] 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/2psg_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=2psg ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The molecular structure of porcine pepsinogen at 1.8 A resolution has been determined by a combination of molecular replacement and multiple isomorphous phasing techniques. The resulting structure was refined by restrained-parameter least-squares methods. The final R factor [formula: see text] is 0.164 for 32,264 reflections with I greater than or equal to sigma (I) in the resolution range of 8.0 to 1.8 A. The model consists of 2785 protein atoms in 370 residues, a phosphoryl group on Ser68 and 238 ordered water molecules. The resulting molecular stereochemistry is consistent with a well-refined crystal structure with co-ordinate accuracy in the range of 0.10 to 0.15 A for the well-ordered regions of the molecule (B less than 15 A2). For the enzyme portion of the zymogen, the root-mean-square difference in C alpha atom co-ordinates with the refined porcine pepsin structure is 0.90 A (284 common atoms) and with the C alpha atoms of penicillopepsin it is 1.63 A (275 common atoms). The additional 44 N-terminal amino acids of the prosegment (Leu1p to Leu44p, using the letter p after the residue number to distinguish the residues of the prosegment) adopt a relatively compact structure consisting of a long beta-strand followed by two approximately orthogonal alpha-helices and a short 3(10)-helix. Intimate contacts, both electrostatic and hydrophobic interactions, are made with residues in the pepsin active site. The N-terminal beta-strand, Leu1p to Leu6p, forms part of the six-stranded beta-sheet common to the aspartic proteinases. In the zymogen the first 13 residues of pepsin, Ile1 to Glu13, adopt a completely different conformation from that of the mature enzyme. The C alpha atom of Ile1 must move approximately 44 A in going from its position in the inactive zymogen to its observed position in active pepsin. Electrostatic interactions of Lys36pN and hydrogen-bonding interactions of Tyr37pOH, and Tyr90H with the two catalytic aspartate groups, Asp32 and Asp215, prevent substrate access to the active site of the zymogen. We have made a detailed comparison of the mammalian pepsinogen fold with the fungal aspartic proteinase fold of penicillopepsin, used for the molecular replacement solution. A structurally derived alignment of the two sequences is presented.

Refined structure of porcine pepsinogen at 1.8 A resolution.,Sielecki AR, Fujinaga M, Read RJ, James MN J Mol Biol. 1991 Jun 20;219(4):671-92. PMID:2056534<ref>PMID:2056534</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 2psg" style="background-color:#fffaf0;"></div>

==See Also==
*[[Pepsin|Pepsin]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Sus scrofa]]
[[Category: James MNG]]
[[Category: Sielecki AR]]