1SGT

REFINED CRYSTAL STRUCTURE OF STREPTOMYCES GRISEUS TRYPSIN AT 1.7 ANGSTROMS RESOLUTION


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Observed: 0.161 

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This is version 1.3 of the entry. See complete history


Literature

Refined crystal structure of Streptomyces griseus trypsin at 1.7 A resolution.

Read, R.J.James, M.N.

(1988) J Mol Biol 200: 523-551

  • DOI: 10.1016/0022-2836(88)90541-4
  • Primary Citation of Related Structures:  
    1SGT

  • PubMed Abstract: 
  • Streptomyces griseus trypsin (SGT) is a bacterial serine proteinase that is more homologous to mammalian than to other bacterial enzymes. The structure of SGT has been solved primarily by molecular replacement, though some low-resolution phase information was supplied by heavy-atom derivatives ...

    Streptomyces griseus trypsin (SGT) is a bacterial serine proteinase that is more homologous to mammalian than to other bacterial enzymes. The structure of SGT has been solved primarily by molecular replacement, though some low-resolution phase information was supplied by heavy-atom derivatives. The mammalian pancreatic serine proteinases bovine trypsin (BT) and alpha-chymotrypsin (CHT) were used as molecular replacement models. Because these proteins have low homology with SGT compared to the majority of other successful replacement models, new strategies were required for molecular replacement to succeed. The model of SGT has been refined at 1.7 A resolution to a final R-factor of 0.161 (1 A = 0.1 nm); the correlation coefficient between all observed and calculated structure factor amplitudes is 0.908. Solvent molecules located in the crystal structure play an important role in stabilizing buried charged and polar groups. An additional contribution to stability can be seen in the fact that the majority of the charged side-chains are involved in ionic interactions, sometimes linking the two domains of SGT. A comparison of SGT with BT shows that the greatest similarities are in the active-site and substrate-binding regions, consistent with their similar substrate specificities. The modeling of complexes of SGT with two inhibitors of BT, pancreatic trypsin inhibitor (PTI) and the third domain of Japanese quail ovomucoid (OMJPQ3), helps to explain why PTI inhibits SGT but OMJPQ3 does not. Like BT, but unlike other bacterial serine proteinases of known structure, SGT has a buried N terminus. SGT has also a well-defined Ca2+-binding site, but this site differs in location from that of BT.


    Related Citations: 
    • Critical Comparison of Comparative Model Building of Streptomyces Griseus Trypsin
      Read, R.J., Brayer, G.D., Jurasek, L., James, M.N.G.
      (1984) Biochemistry 23: 6570

    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
TRYPSINA223Streptomyces griseusMutation(s): 0 
Gene Names: sprT
EC: 3.4.21.4
UniProt
Find proteins for P00775 (Streptomyces griseus)
Explore P00775 
Go to UniProtKB:  P00775
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP00775
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download Ideal Coordinates CCD File 
B [auth A]CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Observed: 0.161 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 72.29α = 90
b = 50.98β = 90
c = 120.09γ = 90
Software Package:
Software NamePurpose
PROLSQrefinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1988-07-16
    Type: Initial release
  • Version 1.1: 2008-03-03
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-11-29
    Changes: Derived calculations, Other