1BIK

X-RAY STRUCTURE OF BIKUNIN FROM THE HUMAN INTER-ALPHA-INHIBITOR COMPLEX


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.253 
  • R-Value Work: 0.205 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The crystal structure of bikunin from the inter-alpha-inhibitor complex: a serine protease inhibitor with two Kunitz domains.

Xu, Y.Carr, P.D.Guss, J.M.Ollis, D.L.

(1998) J.Mol.Biol. 276: 955-966

  • DOI: 10.1006/jmbi.1997.1582

  • PubMed Abstract: 
  • Bikunin is a serine protease inhibitor found in the blood serum and urine of humans and other animals. Its sequence shows internal repetition, suggesting that it contains two domains that resemble bovine pancreatic trypsin inhibitor (BPTI). A fragmen ...

    Bikunin is a serine protease inhibitor found in the blood serum and urine of humans and other animals. Its sequence shows internal repetition, suggesting that it contains two domains that resemble bovine pancreatic trypsin inhibitor (BPTI). A fragment of bikunin has been crystallised, its structure solved and subsequently refined against 2.5 A data. The two BPTI-like domains pack closely together and are related by an approximate 60 degrees rotation combined with a translation. These domains are very similar to each other and other proteins with this fold. The largest variations occur in the loops responsible for protease recognition. The loops of the first domain are unobstructed by the remaining protein. However, the loops of the second domain are close to the first domain and it is possible that protease binding may be affected or, in some cases, abolished by the presence of the first domain. Thus, cleavage of the two domains could alter the substrate specificity of domain II. Bikunin has a hydrophobic patch close to the N terminus of domain I, which is the most likely site for cell-surface receptor binding. In addition, there is a basic patch at one end of domain II that may be responsible for the inhibition of calcium oxalate crystallization in urine.


    Organizational Affiliation

    Research School of Chemistry, Australian National University, Canberra, Australia.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
BIKUNIN
A
147Homo sapiensGene Names: AMBP (HCP, ITIL)
Find proteins for P02760 (Homo sapiens)
Go to Gene View: AMBP
Go to UniProtKB:  P02760
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
NAG
Query on NAG

Download SDF File 
Download CCD File 
A
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.253 
  • R-Value Work: 0.205 
  • Space Group: P 41 21 2
Unit Cell:
Length (Å)Angle (°)
a = 55.300α = 90.00
b = 55.300β = 90.00
c = 146.900γ = 90.00
Software Package:
Software NamePurpose
X-PLORphasing
DENZOdata reduction
SCALEPACKdata scaling
X-PLORrefinement
X-PLORmodel building

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1999-03-16
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Non-polymer description, Version format compliance