2TRM

THE THREE-DIMENSIONAL STRUCTURE OF ASN102 MUTANT OF TRYPSIN. ROLE OF ASP102 IN SERINE PROTEASE CATALYSIS

• PDB DOI: https://doi.org/10.2210/pdb2TRM/pdb

• Classification: HYDROLASE (SERINE PROTEINASE)
• Organism(s): Rattus norvegicus
• Mutation(s): No 


• Deposited: 1988-04-25 Released: 1988-07-16 
• Deposition Author(s): Stroud, R.M., Finer-Moore, J.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.80 Å
• R-Value Observed: 0.157 

Literature

The three-dimensional structure of Asn102 mutant of trypsin: role of Asp102 in serine protease catalysis.

Sprang, S., Standing, T., Fletterick, R.J., Stroud, R.M., Finer-Moore, J., Xuong, N.H., Hamlin, R., Rutter, W.J., Craik, C.S.

(1987) Science 237: 905-909

• PubMed: 3112942 
• DOI: https://doi.org/10.1126/science.3112942
• Primary Citation of Related Structures:  
  1TRM, 2TRM


• PubMed Abstract: 
  

  The structure of the Asn102 mutant of trypsin was determined in order to distinguish whether the reduced activity of the mutant at neutral pH results from an altered active site conformation or from an inability to stabilize a positive charge on the active site histidine. The active site structure of the Asn102 mutant of trypsin is identical to the native enzyme with respect to the specificity pocket, the oxyanion hole, and the orientation of the nucleophilic serine. The observed decrease in rate results from the loss of nucleophilicity of the active site serine. This decreased nucleophilicity may result from stabilization of a His57 tautomer that is unable to accept the serine hydroxyl proton.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 23.97 kDa 
• Atom Count: 1,798 
• Modelled Residue Count: 223 
• Deposited Residue Count: 223 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
TRYPSIN	A	223	Rattus norvegicus	Mutation(s): 0  EC: 3.4.21.4
UniProt
Find proteins for P00763 (Rattus norvegicus) Explore P00763  Go to UniProtKB:  P00763

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
BEN	C [auth A]	BENZAMIDINE C7 H8 N2 PXXJHWLDUBFPOL-UHFFFAOYSA-N
CA	B [auth A]	CALCIUM ION Ca BHPQYMZQTOCNFJ-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.80 Å
• R-Value Observed: 0.157 
• Space Group: I 2 3

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 124.38	α = 90
b = 124.38	β = 90
c = 124.38	γ = 90

Software Package:

Software Name	Purpose
PROLSQ	refinement

Structure Validation

Entry History 

Deposition Data

• Released Date: 1988-07-16 
Deposition Author(s): Stroud, R.M., Finer-Moore, J.

Revision History  

• 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
• Version 1.4: 2024-11-13
  Changes: Data collection, Database references, Derived calculations, Structure summary