2PSG

REFINED STRUCTURE OF PORCINE PEPSINOGEN AT 1.8 ANGSTROMS RESOLUTION


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Observed: 0.164 

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This is version 1.2 of the entry. See complete history


Literature

Refined structure of porcine pepsinogen at 1.8 A resolution.

Sielecki, A.R.Fujinaga, M.Read, R.J.James, M.N.

(1991) J Mol Biol 219: 671-692

  • DOI: 10.1016/0022-2836(91)90664-r
  • Primary Citation of Related Structures:  
    2PSG

  • PubMed Abstract: 
  • 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 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.


    Related Citations: 
    • Molecular Structure of an Aspartic Proteinase Zymogen, Porcine Pepsinogen, at 1.8 Angstroms Resolution
      James, M.N.G., Sielecki, A.R.
      (1986) Nature 319: 33
    • Characterization of Phosphoserine of Pepsinogen Using 31P Nuclear Magnetic Resonance: Corroboration of X-Ray Crystallographic Results
      Williams, S.P., Bridger, W.A., James, M.N.G.
      (1986) Biochemistry 25: 6655

    Organizational Affiliation

    Department of Biochemistry, University of Alberta, Edmonton, Canada.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
PEPSINOGENA370Sus scrofaMutation(s): 0 
Gene Names: PGA
EC: 3.4.23.1
UniProt
Find proteins for P00791 (Sus scrofa)
Explore P00791 
Go to UniProtKB:  P00791
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP00791
Protein Feature View
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  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
SEP
Query on SEP
A L-PEPTIDE LINKINGC3 H8 N O6 PSER
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Observed: 0.164 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 105.78α = 90
b = 43.41β = 91.4
c = 88.58γ = 90
Software Package:
Software NamePurpose
PROLSQrefinement

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1992-10-15
    Type: Initial release
  • Version 1.1: 2008-03-25
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance