4LB1

Crystal structure of human alpha-defensin 1 (HNP1) Y16A/F28A mutant


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.228 
  • R-Value Work: 0.190 

wwPDB Validation 3D Report Full Report


This is version 1.0 of the entry. See complete history

Literature

Single, Double and Quadruple Alanine Substitutions at Oligomeric Interfaces Identify Hydrophobicity as the Key Determinant of Human Neutrophil Alpha Defensin HNP1 Function.

Zhao, L.Tolbert, W.D.Ericksen, B.Zhan, C.Wu, X.Yuan, W.Li, X.Pazgier, M.Lu, W.

(2013) Plos One 8: e78937-e78937

  • DOI: 10.1371/journal.pone.0078937
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • HNP1 is a human alpha defensin that forms dimers and multimers governed by hydrophobic residues, including Tyr¹⁶, Ile²⁰, Leu²⁵, and Phe²⁸. Previously, alanine scanning mutagenesis identified each of these residues and other hydrophobic residues as im ...

    HNP1 is a human alpha defensin that forms dimers and multimers governed by hydrophobic residues, including Tyr¹⁶, Ile²⁰, Leu²⁵, and Phe²⁸. Previously, alanine scanning mutagenesis identified each of these residues and other hydrophobic residues as important for function. Here we report further structural and functional studies of residues shown to interact with one another across oligomeric interfaces: I20A-HNP1 and L25A-HNP1, plus the double alanine mutants I20A/L25A-HNP1 and Y16A/F28A-HNP1, and the quadruple alanine mutant Y16A/I20A/L25A/F28A-HNP1. We tested binding to HIV-1 gp120 and HNP1 by surface plasmon resonance, binding to HIV-1 gp41 and HNP1 by fluorescence polarization, inhibition of anthrax lethal factor, and antibacterial activity using the virtual colony count assay. Similar to the previously described single mutant W26A-HNP1, the quadruple mutant displayed the least activity in all functional assays, followed by the double mutant Y16A/F28A-HNP1. The effects of the L25A and I20A single mutations were milder than the double mutant I20A/L25A-HNP1. Crystallographic studies confirmed the correct folding and disulfide pairing, and depicted an array of dimeric and tetrameric structures. These results indicate that side chain hydrophobicity is the critical factor that determines activity at these positions.


    Organizational Affiliation

    Translational Medicine Center, the First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China ; Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Neutrophil defensin 1
D, E, A, B
30Homo sapiensMutation(s): 2 
Gene Names: DEFA1, DEFA1B (DEF1, DEFA2, MRS)
Find proteins for P59665 (Homo sapiens)
Go to Gene View: DEFA1 DEFA1B
Go to UniProtKB:  P59665
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.228 
  • R-Value Work: 0.190 
  • Space Group: H 3
Unit Cell:
Length (Å)Angle (°)
a = 88.553α = 90.00
b = 88.553β = 90.00
c = 54.110γ = 120.00
Software Package:
Software NamePurpose
PHENIXrefinement
HKL-2000data reduction
PHASESphasing
HKL-2000data collection
HKL-2000data scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-11-27
    Type: Initial release