4DEN

Structural insightsinto potent, specific anti-HIV property of actinohivin; Crystal structure of actinohivin in complex with alpha(1-2) mannobiose moiety of high-mannose type glycan of gp120


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 0.202 
  • R-Value Work: 0.145 
  • R-Value Observed: 0.147 

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This is version 2.1 of the entry. See complete history


Literature

Structural insights into the specific anti-HIV property of actinohivin: structure of its complex with the alpha(1–2)mannobiose moiety of gp120

Hoque, M.M.Suzuki, K.Tsunoda, M.Jiang, J.Zhang, F.Takahashi, A.Ohbayashi, N.Zhang, X.Tanaka, H.Omura, S.Takenaka, A.

(2012) Acta Crystallogr D Biol Crystallogr 68: 1671-1679

  • DOI: https://doi.org/10.1107/S0907444912040498
  • Primary Citation of Related Structures:  
    4DEN

  • PubMed Abstract: 

    Actinohivin (AH) is an actinomycete lectin with a potent specific anti-HIV activity. In order to clarify the structural evidence for its specific binding to the α(1-2)mannobiose (MB) moiety of the D1 chains of high-mannose-type glycans (HMTGs) attached to HIV-1 gp120, the crystal structure of AH in complex with MB has been determined. The AH molecule is composed of three identical structural modules, each of which has a pocket in which an MB molecule is bound adopting a bracket-shaped conformation. This conformation is stabilized through two weak C-H...O hydrogen bonds facilitated by the α(1-2) linkage. The binding features in the three pockets are quite similar to each other, in accordance with the molecular pseudo-threefold symmetry generated from the three tandem repeats in the amino-acid sequence. The shape of the pocket can accept two neighbouring hydroxyl groups of the O(3) and O(4) atoms of the equatorial configuration of the second mannose residue. To recognize these atoms through hydrogen bonds, an Asp residue is located at the bottom of each pocket. Tyr and Leu residues seem to block the movement of the MB molecules. Furthermore, the O(1) atom of the axial configuration of the second mannose residue protrudes from each pocket into an open space surrounded by the conserved hydrophobic residues, suggesting an additional binding site for the third mannose residue of the branched D1 chain of HMTGs. These structural features provide strong evidence indicating that AH is only highly specific for MB and would facilitate the highly specific affinity of AH for any glycoprotein carrying many HMTGs, such as HIV-1 gp120.


  • Organizational Affiliation

    Faculty of Pharmacy, Iwaki Meisei University, 5-5-1 Chuodai-Iino, Iwaki, Fukushima, Japan.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Actinohivin114actinomycete K97-0003Mutation(s): 0 
UniProt
Find proteins for Q9KWN0 (Actinomycete sp. (strain K97-0003))
Explore Q9KWN0 
Go to UniProtKB:  Q9KWN0
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9KWN0
Sequence Annotations
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  • Reference Sequence
Oligosaccharides

Help

Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
alpha-D-mannopyranose-(1-2)-alpha-D-mannopyranose
B, C, D
2N/A
Glycosylation Resources
GlyTouCan:  G53402KW
GlyCosmos:  G53402KW
GlyGen:  G53402KW
Biologically Interesting Molecules (External Reference) 1 Unique
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 0.202 
  • R-Value Work: 0.145 
  • R-Value Observed: 0.147 
  • Space Group: P 21 3
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 56.217α = 90
b = 56.217β = 90
c = 56.217γ = 90
Software Package:
Software NamePurpose
ADSCdata collection
AMoREphasing
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-11-28
    Type: Initial release
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Advisory, Atomic model, Data collection, Derived calculations, Non-polymer description, Structure summary
  • Version 2.1: 2023-11-08
    Changes: Data collection, Database references, Refinement description, Structure summary