1LTO

Human alpha1-tryptase

• PDB DOI: https://doi.org/10.2210/pdb1LTO/pdb

• Classification: HYDROLASE
• Organism(s): Homo sapiens
• Expression System: Komagataella pastoris
• Mutation(s): No 


• Deposited: 2002-05-20 Released: 2003-05-20 
• Deposition Author(s): Marquardt, U., Zettl, F., Huber, R., Bode, W., Sommerhoff, C.P.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.20 Å
• R-Value Free: 0.267 
• R-Value Work: 0.214 
• R-Value Observed: 0.214 

Starting Model: experimental

Literature

The Crystal Structure of Human alpha1-Tryptase Reveals a Blocked Substrate-binding Region

Marquardt, U., Zettl, F., Huber, R., Bode, W., Sommerhoff, C.P.

(2002) J Mol Biol 321: 491-502

• PubMed: 12162961 
• DOI: https://doi.org/10.1016/s0022-2836(02)00625-3
• Primary Citation of Related Structures:  
  1LTO


• PubMed Abstract: 
  

  Human mast cell tryptases represent a subfamily of trypsin-like serine proteinases implicated in asthma. Unlike beta-tryptases, alpha-tryptases apparently are proteolytically inactive. We have solved the 2.2A crystal structure of mature human alpha1-tryptase. It reveals a frame-like tetrameric architecture that, surprisingly, does not require heparin-binding for stability. In marked contrast to beta2-tryptase, the Ser214-Gly219 segment, which normally provides the template for substrate binding, is kinked in alpha-tryptase, thereby blocking its non-primed subsites. This so far unobserved subsite distortion is incompatible with productive substrate binding and processing. alpha-Tryptase apparently is trapped in this off-conformation by repulsions and attractions of the Asp216 side-chain. However, proteolytic activity could be generated by an induced-fit mechanism.

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Organizational Affiliation: 

Max-Planck-Institut für Biochemie, Abteilung Strukturforschung, Am Klopferspitz 18a, D-82152 Martinsried bei, München, Germany.

Biological Assembly 1  

Global Symmetry: Dihedral - D2  (Explore in 3D)
Global Stoichiometry: Homo 4-mer - A4 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 110.93 kDa 
• Atom Count: 8,343 
• Modelled Residue Count: 972 
• Deposited Residue Count: 980 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
alpha tryptase I	A, B, C, D	245	Homo sapiens	Mutation(s): 0  EC: 3.4.21.59
UniProt & NIH Common Fund Data Resources
Find proteins for Q15661 (Homo sapiens) Explore Q15661  Go to UniProtKB:  Q15661
PHAROS:  Q15661 GTEx:  ENSG00000172236

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.20 Å
• R-Value Free: 0.267 
• R-Value Work: 0.214 
• R-Value Observed: 0.214 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 91.441	α = 90
b = 110.685	β = 90
c = 130.092	γ = 90

Software Package:

Software Name	Purpose
MOSFLM	data reduction
SCALA	data scaling
AMoRE	phasing
CNS	refinement
CCP4	data scaling

Structure Validation

Entry History 

Deposition Data

• Released Date: 2003-05-20 
Deposition Author(s): Marquardt, U., Zettl, F., Huber, R., Bode, W., Sommerhoff, C.P.

Revision History  

• Version 1.0: 2003-05-20
  Type: Initial release
  
• Version 1.1: 2008-04-28
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2024-04-03
  Changes: Data collection, Database references, Refinement description
• Version 1.4: 2024-10-09
  Changes: Structure summary