4bn1

Crystal structure of V174M mutant of Aurora-A kinase

spinqualitylabelsall models 4bn1, resolution 2.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4bn1 is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.499Å Ligands: ADP, CA, TPO Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function AURKA_HUMAN Mitotic serine/threonine kinases that contributes to the regulation of cell cycle progression. Associates with the centrosome and the spindle microtubules during mitosis and plays a critical role in various mitotic events including the establishment of mitotic spindle, centrosome duplication, centrosome separation as well as maturation, chromosomal alignment, spindle assembly checkpoint, and cytokinesis. Required for initial activation of CDK1 at centrosomes. Phosphorylates numerous target proteins, including ARHGEF2, BORA, BRCA1, CDC25B, DLGP5, HDAC6, KIF2A, LATS2, NDEL1, PARD3, PPP1R2, PLK1, RASSF1, TACC3, p53/TP53 and TPX2. Regulates KIF2A tubulin depolymerase activity. Required for normal axon formation. Plays a role in microtubule remodeling during neurite extension. Important for microtubule formation and/or stabilization. Also acts as a key regulatory component of the p53/TP53 pathway, and particularly the checkpoint-response pathways critical for oncogenic transformation of cells, by phosphorylating and stabilizing p53/TP53. Phosphorylates its own inhibitors, the protein phosphatase type 1 (PP1) isoforms, to inhibit their activity. Necessary for proper cilia disassembly prior to mitosis. Publication Abstract from PubMed Most protein kinases are regulated through activation loop phosphorylation, but the contributions of individual sites are largely unresolved due to insufficient control over sample phosphorylation. Aurora-A is a mitotic Ser/Thr protein kinase that has two regulatory phosphorylation sites on its activation loop, T287 and T288. While phosphorylation of T288 is known to activate the kinase, the function of T287 phosphorylation is unclear. We applied site-directed mutagenesis and selective chemical modification to specifically introduce bioisosteres for phospho-threonine and other unnatural amino acids at these positions. Modified Aurora-A proteins were characterized using a biochemical assay measuring substrate phosphorylation. Replacement of T288 with glutamate and aspartate weakly stimulated activity. Phospho-cysteine, installed by chemical synthesis from a corresponding cysteine residue introduced at position 288, showed catalytic activity approaching that of the comparable phospho-serine protein. Unnatural amino acid residues, with longer side chains, inserted at position 288 were autophosphorylated and supported substrate phosphorylation. Aurora-A activity is enhanced by phosphorylation at position 287 alone but is suppressed when position 288 is also phosphorylated. This is rationalized by competition between phosphorylated T287 and T288 for a binding site composed of arginines, based on a structure of Aurora-A in which phospho-T287 occupies this site. This is, to our knowledge, the first example of a Ser/Thr kinase whose activity is controlled by the phosphorylation state of adjacent residues in its activation loop. Overall we demonstrate an approach that combines mutagenesis and selective chemical modification of selected cysteine residues to investigate otherwise impenetrable aspects of kinase regulation. Insights into Aurora-A kinase activation using unnatural amino acids incorporated by chemical modification.,Rowan FC, Richards M, Bibby RA, Thompson A, Bayliss R, Blagg J ACS Chem Biol. 2013 Oct 18;8(10):2184-91. doi: 10.1021/cb400425t. Epub 2013 Aug, 7. PMID:23924325 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Serine/threonine protein kinase 3D structures

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