1QFT

HISTAMINE BINDING PROTEIN FROM FEMALE BROWN EAR RHIPICEPHALUS APPENDICULATUS

• PDB DOI: https://doi.org/10.2210/pdb1QFT/pdb

• Classification: LIGAND BINDING PROTEIN
• Organism(s): Rhipicephalus appendiculatus
• Expression System: Spodoptera
• Mutation(s): No 


• Deposited: 1999-04-14 Released: 2000-04-19 
• Deposition Author(s): Paesen, G.C., Adams, P.L., Harlos, K., Nuttal, P.A., Stuart, D.I.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.25 Å
• R-Value Work: 0.184 

Literature

Tick histamine-binding proteins: isolation, cloning, and three-dimensional structure.

Paesen, G.C., Adams, P.L., Harlos, K., Nuttall, P.A., Stuart, D.I.

(1999) Mol Cell 3: 661-671

• PubMed: 10360182 
• DOI: https://doi.org/10.1016/s1097-2765(00)80359-7
• Primary Citation of Related Structures:  
  1QFT, 1QFV


• PubMed Abstract: 
  

  High-affinity histamine-binding proteins (HBPs) were discovered in the saliva of Rhipicephalus appendiculatus ticks. Their ability to outcompete histamine receptors indicates that they suppress inflammation during blood feeding. The crystal structure of a histamine-bound HBP, determined at 1.25 A resolution, reveals a lipocalin fold novel in containing two binding sites for the same ligand. The sites are orthogonally arranged and highly rigid and form an internal surface of unusual polar character that complements the physicochemical properties of histamine. As soluble receptors of histamine, HBPs offer a new strategy for controlling histamine-based diseases.

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Organizational Affiliation: 

Natural Environment Research Council, Institute of Virology and Environmental Microbiology, Oxford, United Kingdom. [e-mail]

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Biological Assembly 2  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 2 assigned by authors.

Macromolecule Content

• Total Structure Weight: 40.07 kDa 
• Atom Count: 3,305 
• Modelled Residue Count: 345 
• Deposited Residue Count: 350 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
PROTEIN (FEMALE-SPECIFIC HISTAMINE BINDING PROTEIN 2)	A, B	175	Rhipicephalus appendiculatus	Mutation(s): 0
UniProt
Find proteins for O77421 (Rhipicephalus appendiculatus) Explore O77421  Go to UniProtKB:  O77421

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
HSM	C [auth A], D [auth A], E [auth B], F [auth B]	HISTAMINE C5 H9 N3 NTYJJOPFIAHURM-UHFFFAOYSA-N

Binding Affinity Annotations
ID	Source	Binding Affinity
HSM	PDBBind:  1QFT	Kd: 1.7 (nM) from 1 assay(s)

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.25 Å
• R-Value Work: 0.184 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 77.42	α = 90
b = 74.79	β = 90
c = 78.52	γ = 90

Software Package:

Software Name	Purpose
DENZO	data reduction
SCALEPACK	data scaling
X-PLOR	refinement

Structure Validation

Entry History 

Deposition Data

• Released Date: 2000-04-19 
Deposition Author(s): Paesen, G.C., Adams, P.L., Harlos, K., Nuttal, P.A., Stuart, D.I.

Revision History  

• Version 1.0: 2000-04-19
  Type: Initial release
  
• Version 1.1: 2008-04-26
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2023-12-27
  Changes: Data collection, Database references, Derived calculations
• Version 1.4: 2024-10-16
  Changes: Structure summary