1qb3
CRYSTAL STRUCTURE OF THE CELL CYCLE REGULATORY PROTEIN CKS1CRYSTAL STRUCTURE OF THE CELL CYCLE REGULATORY PROTEIN CKS1
Structural highlights
FunctionCKS1_YEAST Binds to the catalytic subunit of the cyclin dependent kinase (CDC28) and is essential for its biological function. 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 PubMedBACKGROUND: The Saccharomyces cerevisiae protein Cks1 (cyclin-dependent kinase subunit 1) is essential for cell-cycle progression. The biological function of Cks1 can be modulated by a switch between two distinct molecular assemblies: the single domain fold, which results from the closing of a beta-hinge motif, and the intersubunit beta-strand interchanged dimer, which arises from the opening of the beta-hinge motif. The crystal structure of a cyclin-dependent kinase (Cdk) in complex with the human Cks homolog CksHs1 single-domain fold revealed the importance of conserved hydrophobic residues and charged residues within the beta-hinge motif. RESULTS: The 3.0 A resolution Cks1 structure reveals the strict structural conservation of the Cks alpha/beta-core fold and the beta-hinge motif. The beta hinge identified in the Cks1 structure includes a novel pivot and exposes a cluster of conserved tyrosine residues that are involved in Cdk binding but are sequestered in the beta-interchanged Cks homolog suc1 dimer structure. This Cks1 structure confirms the conservation of the Cks anion-binding site, which interacts with sidechain residues from the C-terminal alpha helix of another subunit in the crystal. CONCLUSIONS: The Cks1 structure exemplifies the conservation of the beta-interchanged dimer and the anion-binding site in evolutionarily distant yeast and human Cks homologs. Mutational analyses including in vivo rescue of CKS1 disruption support the dual functional roles of the beta-hinge residue Glu94, which participates in Cdk binding, and of the anion-binding pocket that is located 22 A away and on an opposite face to Glu94. The Cks1 structure suggests a biological role for the beta-interchanged dimer and the anion-binding site in targeting Cdks to specific phosphoproteins during cell-cycle progression. Crystal structure and mutational analysis of the Saccharomyces cerevisiae cell cycle regulatory protein Cks1: implications for domain swapping, anion binding and protein interactions.,Bourne Y, Watson MH, Arvai AS, Bernstein SL, Reed SI, Tainer JA Structure. 2000 Aug 15;8(8):841-50. PMID:10997903[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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