5H7V

Structure of full-length extracellular domain of HAI-1 at pH 4.6


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.82 Å
  • R-Value Free: 0.328 
  • R-Value Work: 0.253 
  • R-Value Observed: 0.256 

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This is version 1.2 of the entry. See complete history


Literature

The crystal structure of a multidomain protease inhibitor (HAI-1) reveals the mechanism of its auto-inhibition

Liu, M.Yuan, C.Jensen, J.K.Zhao, B.Jiang, Y.Jiang, L.Huang, M.

(2017) J Biol Chem 292: 8412-8423

  • DOI: 10.1074/jbc.M117.779256
  • Primary Citation of Related Structures:  
    5H7V

  • PubMed Abstract: 
  • Hepatocyte growth factor activator inhibitor 1 (HAI-1) is a membrane-bound multidomain protein essential to the integrity of the basement membrane during placental development and is also important in maintaining postnatal homeostasis in many tissues. HAI-1 is a Kunitz-type serine protease inhibitor, and soluble fragments of HAI-1 with variable lengths have been identified in vivo The full-length extracellular portion of HAI-1 (sHAI-1) shows weaker inhibitory activity toward target proteases than the smaller fragments, suggesting auto-inhibition of HAI-1 ...

    Hepatocyte growth factor activator inhibitor 1 (HAI-1) is a membrane-bound multidomain protein essential to the integrity of the basement membrane during placental development and is also important in maintaining postnatal homeostasis in many tissues. HAI-1 is a Kunitz-type serine protease inhibitor, and soluble fragments of HAI-1 with variable lengths have been identified in vivo The full-length extracellular portion of HAI-1 (sHAI-1) shows weaker inhibitory activity toward target proteases than the smaller fragments, suggesting auto-inhibition of HAI-1. However, this possible regulatory mechanism has not yet been evaluated. Here, we solved the crystal structure of sHAI-1 and determined the solution structure by small-angle X-ray scattering. These structural analyses revealed that, despite the presence of long linkers, sHAI-1 exists in a compact conformation in which sHAI-1 active sites in Kunitz domain 1 are sterically blocked by neighboring structural elements. We also found that in the presence of target proteases, sHAI-1 adopts an extended conformation that disables the auto-inhibition effect. Our results also reveal the roles of non-inhibitory domains of this multidomain protein and explain the low activity of the full-length protein. The structural insights gained here improve our understanding of the regulation of HAI-1 inhibitory activities and point to new approaches for better controlling these activities.


    Organizational Affiliation

    the College of Chemistry, Fuzhou University, Fuzhou, Fujian 350108, China.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Kunitz-type protease inhibitor 1A421Homo sapiensMutation(s): 0 
Gene Names: SPINT1HAI1UNQ223/PRO256
UniProt & NIH Common Fund Data Resources
Find proteins for O43278 (Homo sapiens)
Explore O43278 
Go to UniProtKB:  O43278
PHAROS:  O43278
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.82 Å
  • R-Value Free: 0.328 
  • R-Value Work: 0.253 
  • R-Value Observed: 0.256 
  • Space Group: P 41 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 95.62α = 90
b = 95.62β = 90
c = 124.58γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
PDB_EXTRACTdata extraction
xia2data reduction
xia2data scaling
PHENIXphasing

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

  • Deposited Date: 2016-11-21 
  • Released Date: 2017-03-29 
  • Deposition Author(s): Liu, M., Huang, M.

Revision History  (Full details and data files)

  • Version 1.0: 2017-03-29
    Type: Initial release
  • Version 1.1: 2017-04-19
    Changes: Database references
  • Version 1.2: 2017-05-31
    Changes: Database references