3iq7

Crystal Structure of human Haspin in complex with 5-Iodotubercidin

spinqualitylabelsall models 3iq7, resolution 2.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3iq7 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. Ligands: 5ID, EDO, IOD, PO4 Gene: GSG2 (Homo sapiens) Activity: Non-specific serine/threonine protein kinase, with EC number 2.7.11.1 Resources: FirstGlance, OCA, RCSB, PDBsum Function [HASP_HUMAN] Serine/threonine-protein kinase that phosphorylates histone H3 at 'Ser-3' (H3T3ph) during mitosis. This positions and activates AURKB and other components of the chromosomal passenger complex (CPC) at centromeres to ensure proper chromatid cohesion, metaphase alignment and normal progression through the cell cycle. 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 PubMed The protein kinase haspin/Gsg2 plays an important role in mitosis, where it specifically phosphorylates Thr-3 in histone H3 (H3T3). Its protein sequence is only weakly homologous to other protein kinases and lacks the highly conserved motifs normally required for kinase activity. Here we report structures of human haspin in complex with ATP and the inhibitor iodotubercidin. These structures reveal a constitutively active kinase conformation, stabilized by haspin-specific inserts. Haspin also has a highly atypical activation segment well adapted for specific recognition of the basic histone tail. Despite the lack of a DFG motif, ATP binding to haspin is similar to that in classical kinases; however, the ATP gamma-phosphate forms hydrogen bonds with the conserved catalytic loop residues Asp-649 and His-651, and a His651Ala haspin mutant is inactive, suggesting a direct role for the catalytic loop in ATP recognition. Enzyme kinetic data show that haspin phosphorylates substrate peptides through a rapid equilibrium random mechanism. A detailed analysis of histone modifications in the neighborhood of H3T3 reveals that increasing methylation at Lys-4 (H3K4) strongly decreases substrate recognition, suggesting a key role of H3K4 methylation in the regulation of haspin activity. Structure and functional characterization of the atypical human kinase haspin.,Eswaran J, Patnaik D, Filippakopoulos P, Wang F, Stein RL, Murray JW, Higgins JM, Knapp S Proc Natl Acad Sci U S A. 2009 Dec 1;106(48):20198-203. Epub 2009 Nov 16. PMID:19918057 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Serine/threonine protein kinase

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