Crystal structure of the ankyrin-binding domain of human erythroid spectrin

Experimental Data Snapshot

  • Resolution: 2.10 Å
  • R-Value Free: 0.252 
  • R-Value Work: 0.210 
  • R-Value Observed: 0.215 

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The structure of the ankyrin-binding site of {beta}-spectrin reveals how tandem spectrin-repeats generate unique ligand-binding properties

Stabach, P.R.Simonovic, I.Ranieri, M.A.Aboodi, M.S.Steitz, T.A.Simonovic, M.Morrow, J.S.

(2009) Blood 113: 5377-5384

  • DOI: https://doi.org/10.1182/blood-2008-10-184291
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Spectrin and ankyrin participate in membrane organization, stability, signal transduction, and protein targeting; their interaction is critical for erythrocyte stability. Repeats 14 and 15 of betaI-spectrin are crucial for ankyrin recognition, yet the way spectrin binds ankyrin while preserving its repeat structure is unknown. We have solved the crystal structure of the betaI-spectrin 14,15 di-repeat unit to 2.1 A resolution and found 14 residues critical for ankyrin binding that map to the end of the helix C of repeat 14, the linker region, and the B-C loop of repeat 15. The tilt (64 degrees) across the 14,15 linker is greater than in any published di-repeat structure, suggesting that the relative positioning of the two repeats is important for ankyrin binding. We propose that a lack of structural constraints on linker and inter-helix loops allows proteins containing spectrin-like di-repeats to evolve diverse but specific ligand-recognition sites without compromising the structure of the repeat unit. The linker regions between repeats are thus critical determinants of both spectrin's flexibility and polyfunctionality. The putative coupling of flexibility and ligand binding suggests a mechanism by which spectrin might participate in mechanosensory regulation.

  • Organizational Affiliation

    Department of Pathology, Yale University, New Haven, CT 06520, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Spectrin beta chain, erythrocyte218Homo sapiensMutation(s): 0 
Gene Names: SPTBSPTB1
UniProt & NIH Common Fund Data Resources
Find proteins for P11277 (Homo sapiens)
Explore P11277 
Go to UniProtKB:  P11277
PHAROS:  P11277
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP11277
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.10 Å
  • R-Value Free: 0.252 
  • R-Value Work: 0.210 
  • R-Value Observed: 0.215 
  • Space Group: F 2 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 74.823α = 90
b = 111.746β = 90
c = 127.734γ = 90
Software Package:
Software NamePurpose
CBASSdata collection
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-02-10
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2011-07-20
    Changes: Refinement description