1SEL

CRYSTAL STRUCTURE OF SELENOSUBTILISIN AT 2.0-ANGSTROMS RESOLUTION


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Work: 0.173 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Crystal structure of selenosubtilisin at 2.0-A resolution.

Syed, R.Wu, Z.P.Hogle, J.M.Hilvert, D.

(1993) Biochemistry 32: 6157-6164


  • PubMed Abstract: 
  • The three-dimensional structure of selenosubtilisin, an artificial selenoenzyme, has been solved at 2.0-A resolution by the method of molecular replacement. Selenosubtilisin is a chemical derivative of the bacterial serine protease subtilisin in whic ...

    The three-dimensional structure of selenosubtilisin, an artificial selenoenzyme, has been solved at 2.0-A resolution by the method of molecular replacement. Selenosubtilisin is a chemical derivative of the bacterial serine protease subtilisin in which the catalytically essential serine residue has been replaced with a selenocysteine. Its unique hydrolytic and redox properties reflect the intrinsic chemical reactivity of the selenium prosthetic group. Structural analysis of the modified protein reveals that the selenium moiety is selectively incorporated into the side chain of residue 221 and confirms the seleninic acid oxidation state expected from treatment of the enzyme with hydrogen peroxide prior to crystallization. Although the seleninic acid replaces the essential nucleophile in the enzyme's catalytic triad and introduces a negative charge into the active site, the interaction between His64 and Asp32 is not altered by the modification. Hydrogen bonds from the oxygen atoms of the seleninic acid to His64 and to Asn155 in the oxyanion hole confine the prosthetic group to a single well-defined conformation within the active site. These interactions thus provide a structural basis for understanding the seleninic acid's unusually low pKa, the enzyme's relatively sluggish rate of reaction with thiols, and its much more efficient peroxidase activity. Aside from the active site region, the structure of the protein is essentially the same as that previously reported for native subtilisin Carlsberg, indicating the viability of chemical modification strategies for incorporating site-specific changes into the protein backbone. Comparison of the three-dimensional structures of selenosubtilisin and glutathione peroxidase, an important naturally occurring selenoenzyme, provides the means to evaluate how the function of the selenium prosthetic group varies with molecular context.


    Organizational Affiliation

    Department of Chemistry, Scripps Research Institute, La Jolla, California 92037.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
SELENOSUBTILISIN
A, B
274Bacillus licheniformisMutation(s): 0 
Gene Names: apr
EC: 3.4.21.62
Find proteins for P00780 (Bacillus licheniformis)
Go to UniProtKB:  P00780
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download SDF File 
Download CCD File 
A, B
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
SE7
Query on SE7
A, B
L-PEPTIDE LINKINGC3 H7 N O4 SeSEC
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Work: 0.173 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 75.800α = 90.00
b = 65.400β = 107.30
c = 53.300γ = 90.00
Software Package:
Software NamePurpose
X-PLORphasing
X-PLORmodel building
X-PLORrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1993-10-31
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2013-12-25
    Type: Non-polymer description