Crystal structure of CLASP1 TOG2 domain at 1.78A resolution

Experimental Data Snapshot

  • Resolution: 1.78 Å
  • R-Value Free: 0.221 
  • R-Value Work: 0.177 
  • R-Value Observed: 0.179 

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Structures of TOG1 and TOG2 from the human microtubule dynamics regulator CLASP1.

Leano, J.B.Slep, K.C.

(2019) PLoS One 14: e0219823-e0219823

  • DOI: https://doi.org/10.1371/journal.pone.0219823
  • Primary Citation of Related Structures:  
    6MQ5, 6MQ7

  • PubMed Abstract: 

    Tubulin-binding TOG domains are found arrayed in a number of proteins that regulate microtubule dynamics. While much is known about the structure and function of TOG domains from the XMAP215 microtubule polymerase family, less in known about the TOG domain array found in animal CLASP family members. The animal CLASP TOG array promotes microtubule pause, potentiates rescue, and limits catastrophe. How structurally distinct the TOG domains of animal CLASP are from one another, from XMAP215 family TOG domains, and whether a specific order of structurally distinct TOG domains in the TOG array is conserved across animal CLASP family members is poorly understood. We present the x-ray crystal structures of Homo sapiens (H.s.) CLASP1 TOG1 and TOG2. The structures of H.s. CLASP1 TOG1 and TOG2 are distinct from each other and from the previously determined structure of Mus musculus (M.m.) CLASP2 TOG3. Comparative analyses of CLASP family TOG domain structures determined to date across species and paralogs supports a conserved CLASP TOG array paradigm in which structurally distinct TOG domains are arrayed in a specific order. H.s. CLASP1 TOG1 bears structural similarity to the free-tubulin binding TOG domains of the XMAP215 family but lacks many of the key tubulin-binding determinants found in XMAP215 family TOG domains. This aligns with studies that report that animal CLASP family TOG1 domains cannot bind free tubulin or microtubules. In contrast, animal CLASP family TOG2 and TOG3 domains have reported microtubule-binding activity but are structurally distinct from the free-tubulin binding TOG domains of the XMAP215 family. H.s. CLASP1 TOG2 has a convex architecture, predicted to engage a hyper-curved tubulin state that may underlie its ability to limit microtubule catastrophe and promote rescue. M.m. CLASP2 TOG3 has unique structural elements in the C-terminal half of its α-solenoid domain that our modeling studies implicate in binding to laterally-associated tubulin subunits in the microtubule lattice in a mode similar to, yet distinct from those predicted for the XMAP215 family TOG4 domain. The potential ability of the animal CLASP family TOG3 domain to engage lateral tubulin subunits may underlie the microtubule rescue activity ascribed to the domain. These findings highlight the structural diversity of TOG domains within the CLASP family TOG array and provide a molecular foundation for understanding CLASP-dependent effects on microtubule dynamics.

  • Organizational Affiliation

    Program in Molecular and Cellular Biophysics, University of North Carolina, Chapel Hill, North Carolina, United States of America.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
CLIP-associating protein 1
A, B
273Homo sapiensMutation(s): 0 
Gene Names: CLASP1KIAA0622MAST1
UniProt & NIH Common Fund Data Resources
Find proteins for Q7Z460 (Homo sapiens)
Explore Q7Z460 
Go to UniProtKB:  Q7Z460
GTEx:  ENSG00000074054 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ7Z460
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.78 Å
  • R-Value Free: 0.221 
  • R-Value Work: 0.177 
  • R-Value Observed: 0.179 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 51.606α = 90
b = 67.352β = 98.25
c = 81.022γ = 90
Software Package:
Software NamePurpose
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesR01GM094415

Revision History  (Full details and data files)

  • Version 1.0: 2019-07-17
    Type: Initial release
  • Version 1.1: 2019-07-31
    Changes: Data collection, Database references
  • Version 1.2: 2020-01-01
    Changes: Author supporting evidence
  • Version 1.3: 2023-10-11
    Changes: Data collection, Database references, Refinement description