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 

wwPDB Validation 3D Report Full Report


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

  • 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 ...

    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

    From the State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China, mhuang@fjirsm.ac.cn.,the Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark, and.,the College of Chemistry, Fuzhou University, Fuzhou, Fujian 350108, China.,the University of Chinese Academy of Sciences, Beijing 100049, China.,the College of Bioscience and Biotechnology, Fuzhou University, Fuzhou, Fujian, 350108, China, cyuan@fzu.edu.cn.,From the State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Kunitz-type protease inhibitor 1
A
421Homo sapiensMutation(s): 0 
Gene Names: SPINT1 (HAI1)
Find proteins for O43278 (Homo sapiens)
Go to Gene View: SPINT1
Go to UniProtKB:  O43278
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.82 Å
  • R-Value Free: 0.328 
  • R-Value Work: 0.253 
  • Space Group: P 41 21 2
Unit Cell:
Length (Å)Angle (°)
a = 95.620α = 90.00
b = 95.620β = 90.00
c = 124.580γ = 90.00
Software Package:
Software NamePurpose
xia2data scaling
PHENIXphasing
PHENIXrefinement
xia2data reduction
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

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

Revision History 

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