4RKJ

Crystal structure of thrombin mutant S195T (free form)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.207 
  • R-Value Work: 0.156 
  • R-Value Observed: 0.159 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Why ser and not thr brokers catalysis in the trypsin fold.

Pelc, L.A.Chen, Z.Gohara, D.W.Vogt, A.D.Pozzi, N.Di Cera, E.

(2015) Biochemistry 54: 1457-1464

  • DOI: https://doi.org/10.1021/acs.biochem.5b00014
  • Primary Citation of Related Structures:  
    4RKJ, 4RKO

  • PubMed Abstract: 

    Although Thr is equally represented as Ser in the human genome and as a nucleophile is as good as Ser, it is never found in the active site of the large family of trypsin-like proteases that utilize the Asp/His/Ser triad. The molecular basis of the preference of Ser over Thr in the trypsin fold was investigated with X-ray structures of the thrombin mutant S195T free and bound to an irreversible active site inhibitor. In the free form, the methyl group of T195 is oriented toward the incoming substrate in a conformation seemingly incompatible with productive binding. In the bound form, the side chain of T195 is reoriented for efficient substrate acylation without causing steric clash within the active site. Rapid kinetics prove that this change is due to selection of an active conformation from a preexisting ensemble of reactive and unreactive rotamers whose relative distribution determines the level of activity of the protease. Consistent with these observations, the S195T substitution is associated with a weak yet finite activity that allows identification of an unanticipated important role for S195 as the end point of allosteric transduction in the trypsin fold. The S195T mutation abrogates the Na(+)-dependent enhancement of catalytic activity in thrombin, activated protein C, and factor Xa and significantly weakens the physiologically important allosteric effects of thrombomodulin on thrombin and of cofactor Va on factor Xa. The evolutionary selection of Ser over Thr in trypsin-like proteases was therefore driven by the need for high catalytic activity and efficient allosteric regulation.


  • Organizational Affiliation

    Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine , St. Louis, Missouri 63104, United States.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Thrombin light chain34Homo sapiensMutation(s): 0 
Gene Names: F2
EC: 3.4.21.5
UniProt & NIH Common Fund Data Resources
Find proteins for P00734 (Homo sapiens)
Explore P00734 
Go to UniProtKB:  P00734
PHAROS:  P00734
GTEx:  ENSG00000180210 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP00734
Sequence Annotations
Expand
  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Thrombin heavy chain259Homo sapiensMutation(s): 1 
Gene Names: F2
EC: 3.4.21.5
UniProt & NIH Common Fund Data Resources
Find proteins for P00734 (Homo sapiens)
Explore P00734 
Go to UniProtKB:  P00734
PHAROS:  P00734
GTEx:  ENSG00000180210 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP00734
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.207 
  • R-Value Work: 0.156 
  • R-Value Observed: 0.159 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 61.415α = 90
b = 91.114β = 90
c = 50.553γ = 90
Software Package:
Software NamePurpose
CrystalCleardata collection
MOLREPphasing
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2015-03-11
    Type: Initial release
  • Version 1.1: 2023-09-20
    Changes: Data collection, Database references, Derived calculations, Refinement description