title: Structure of a Blinkin-BUBR1 complex reveals an interaction crucial for kinetochore-mitotic checkpoint regulation via an unanticipated binding Site.
abstract: The maintenance of genomic stability relies on the spindle assembly checkpoint (SAC), which ensures accurate chromosome segregation by delaying the onset of anaphase until all chromosomes are properly bioriented and attached to the mitotic spindle. BUB1 and BUBR1 kinases are central for this process and by interacting with Blinkin, link the SAC with the kinetochore, the macromolecular assembly that connects microtubules with centromeric DNA. Here, we identify the Blinkin motif critical for interaction with BUBR1, define the stoichiometry and affinity of the interaction, and present a 2.2 Å resolution crystal structure of the complex. The structure defines an unanticipated BUBR1 region responsible for the interaction and reveals a novel Blinkin motif that undergoes a disorder-to-order transition upon ligand binding. We also show that substitution of several BUBR1 residues engaged in binding Blinkin leads to defects in the SAC, thus providing the first molecular details of the recognition mechanism underlying kinetochore-SAC signaling.
authors: Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK. victor@cryst.bioc.cam.ac.uk
authors: Victor M
authors: VM
authors: Bolanos-Garcia
authors: Tiziana
authors: T
authors: Lischetti
authors: Dijana
authors: D
authors: Matak-Vinković
authors: Ernesto
authors: E
authors: Cota
authors: Pete J
authors: PJ
authors: Simpson
authors: Dimitri Y
authors: DY
authors: Chirgadze
authors: David R
authors: DR
authors: Spring
authors: Carol V
authors: CV
authors: Robinson
authors: Jakob
authors: J
authors: Nilsson
authors: Tom L
authors: TL
authors: Blundell
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D064199:Cdc20 Proteins; D018797:Cell Cycle Proteins / Q000378:metabolism; D018360:Crystallography, X-Ray; D006367:HeLa Cells; D006801:Humans; D018386:Kinetochores / Q000502:physiology*; D059566:M Phase Cell Cycle Checkpoints; D008869:Microtubule-Associated Proteins / Q000737:chemistry* / Q000378:metabolism; D008938:Mitosis; D008969:Molecular Sequence Data; D046912:Multiprotein Complexes / Q000737:chemistry*; D000075223:Poly-ADP-Ribose Binding Proteins; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D020798:Two-Hybrid System Techniques
chemical_list: C489444:BUB3 protein, human; D064199:Cdc20 Proteins; D018797:Cell Cycle Proteins; C472643:Knl1 protein, human; D008869:Microtubule-Associated Proteins; D046912:Multiprotein Complexes; D000075223:Poly-ADP-Ribose Binding Proteins; C577488:CDC20 protein, human; C584277:BUB1 protein, human; C090464:Bub1 spindle checkpoint protein; D017346:Protein Serine-Threonine Kinases