Structure of human Bub1 kinase domain phosphorylated at Ser969

Experimental Data Snapshot

  • Resolution: 2.40 Å
  • R-Value Free: 0.245 
  • R-Value Work: 0.210 
  • R-Value Observed: 0.212 

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Role of Intrinsic and Extrinsic Factors in the Regulation of the Mitotic Checkpoint Kinase Bub1.

Breit, C.Bange, T.Petrovic, A.Weir, J.R.Muller, F.Vogt, D.Musacchio, A.

(2015) PLoS One 10: e0144673-e0144673

  • DOI: https://doi.org/10.1371/journal.pone.0144673
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The spindle assembly checkpoint (SAC) monitors microtubule attachment to kinetochores to ensure accurate sister chromatid segregation during mitosis. The SAC members Bub1 and BubR1 are paralogs that underwent significant functional specializations during evolution. We report an in-depth characterization of the kinase domains of Bub1 and BubR1. BubR1 kinase domain binds nucleotides but is unable to deliver catalytic activity in vitro. Conversely, Bub1 is an active kinase regulated by intra-molecular phosphorylation at the P+1 loop. The crystal structure of the phosphorylated Bub1 kinase domain illustrates a hitherto unknown conformation of the P+1 loop docked into the active site of the Bub1 kinase. Both Bub1 and BubR1 bind Bub3 constitutively. A hydrodynamic characterization of Bub1:Bub3 and BubR1:Bub3 demonstrates both complexes to have 1:1 stoichiometry, with no additional oligomerization. Conversely, Bub1:Bub3 and BubR1:Bub3 combine to form a heterotetramer. Neither BubR1:Bub3 nor Knl1, the kinetochore receptor of Bub1:Bub3, modulate the kinase activity of Bub1 in vitro, suggesting autonomous regulation of the Bub1 kinase domain. We complement our study with an analysis of the Bub1 substrates. Our results contribute to the mechanistic characterization of a crucial cell cycle checkpoint.

  • Organizational Affiliation

    Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227, Dortmund, Germany.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Mitotic checkpoint serine/threonine-protein kinase BUB1
A, B
365Homo sapiensMutation(s): 0 
Gene Names: BUB1BUB1L
UniProt & NIH Common Fund Data Resources
Find proteins for O43683 (Homo sapiens)
Explore O43683 
Go to UniProtKB:  O43683
PHAROS:  O43683
GTEx:  ENSG00000169679 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO43683
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.40 Å
  • R-Value Free: 0.245 
  • R-Value Work: 0.210 
  • R-Value Observed: 0.212 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 62.38α = 90
b = 66.34β = 98.34
c = 106.54γ = 90
Software Package:
Software NamePurpose
XDSdata reduction
XSCALEdata scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
European Research Council (ERC) Advanced Investigator award RECEPIANCE--
German Research Foundation1093

Revision History  (Full details and data files)

  • Version 1.0: 2015-12-16
    Type: Initial release
  • Version 1.1: 2015-12-23
    Changes: Database references
  • Version 1.2: 2016-10-19
    Changes: Database references
  • Version 1.3: 2024-01-10
    Changes: Author supporting evidence, Data collection, Database references, Derived calculations, Refinement description