2qyf
From Proteopedia
Crystal structure of the Mad2/p31(comet)/Mad2-binding peptide ternary complex
Structural highlights
Function[MD2L1_HUMAN] Component of the spindle-assembly checkpoint that prevents the onset of anaphase until all chromosomes are properly aligned at the metaphase plate. Required for the execution of the mitotic checkpoint which monitors the process of kinetochore-spindle attachment and inhibits the activity of the anaphase promoting complex by sequestering CDC20 until all chromosomes are aligned at the metaphase plate.[1] [2] [3] [MD2BP_HUMAN] May function to silence the spindle checkpoint and allow mitosis to proceed through anaphase by binding MAD2L1 after it has become dissociated from the MAD2L1-CDC20 complex.[4] [5] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe status of spindle checkpoint signaling depends on the balance of two opposing dynamic processes that regulate the highly unusual two-state behavior of Mad2. In mitosis, a Mad1-Mad2 core complex recruits cytosolic Mad2 to kinetochores through Mad2 dimerization and converts Mad2 to a conformer amenable to Cdc20 binding, thereby facilitating checkpoint activation. p31(comet) inactivates the checkpoint through binding to Mad1- or Cdc20-bound Mad2, thereby preventing Mad2 activation and promoting the dissociation of the Mad2-Cdc20 complex. Here, we report the crystal structure of the Mad2-p31(comet) complex. The C-terminal region of Mad2 that undergoes rearrangement in different Mad2 conformers is a major structural determinant for p31(comet) binding, explaining the specificity of p31(comet) toward Mad1- or Cdc20-bound Mad2. p31(comet) adopts a fold strikingly similar to that of Mad2 and binds at the dimerization interface of Mad2. Thus, p31(comet) exploits the two-state behavior of Mad2 to block its activation by acting as an "anti-Mad2." p31comet blocks Mad2 activation through structural mimicry.,Yang M, Li B, Tomchick DR, Machius M, Rizo J, Yu H, Luo X Cell. 2007 Nov 16;131(4):744-55. PMID:18022368[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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