Human alpha1-tryptase

Experimental Data Snapshot

  • Resolution: 2.20 Å
  • R-Value Free: 0.267 
  • R-Value Work: 0.214 
  • R-Value Observed: 0.214 

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This is version 1.3 of the entry. See complete history


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

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

  • 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.

  • Organizational Affiliation

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

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
alpha tryptase I
A, B, C, D
245Homo sapiensMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for Q15661 (Homo sapiens)
Explore Q15661 
Go to UniProtKB:  Q15661
PHAROS:  Q15661
GTEx:  ENSG00000172236 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ15661
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • 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 = 91.441α = 90
b = 110.685β = 90
c = 130.092γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling
CCP4data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • 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