The crystal structure of the human polo-like kinase-1 polo box domain and its phospho-peptide complex.
Human polo-like kinase Plk1 localizes to the centrosomes, kinetochores and central spindle structures during mitosis. It plays an essential role in promoting mitosis and cytokinesis through phosphorylation of a number of different substrates. Kinase activity is regulated by a conserved C-terminal domain, termed the polo box domain (PBD), which acts both as an autoinhibitory domain and as a subcellular localization domain. We have determined the crystal structure of Plk1 PBD (residues 367-603) to 2.2 A resolution and the structure of a phospho-peptide-PBD (residues 345-603) complex to 2.3 A resolution. The two polo boxes of the PBD exhibit identical folds based on a six-stranded beta-sheet and an alpha-helix, despite only 12% sequence identity. The phospho-peptide binds at a site between the two polo boxes. It makes a short antiparallel beta-sheet connection and critical contacts to residues Trp414, Leu490, His538 and Lys540. Most of these residues had been shown to be important for biological activity through mutational studies. The results provide an explanation for phospho-peptide recognition and create the basis for new functional studies.
Cheng
Kin-Yip
KY
Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
Lowe
Edward D
ED
Sinclair
John
J
Nigg
Erich A
EA
Johnson
Louise N
LN
D000595:Amino Acid Sequence; D018797:Cell Cycle Proteins; D018360:Crystallography, X-Ray; D006801:Humans; D046911:Macromolecular Substances; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017510:Protein Folding; D011494:Protein Kinases / Q000737:chemistry* / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000235:genetics; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011518:Proto-Oncogene Proteins; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D055672:Static Electricity; D000097869:Polo-Like Kinase 1
D018797:Cell Cycle Proteins; D046911:Macromolecular Substances; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D011994:Recombinant Proteins; D000097869:Polo-Like Kinase 1; C490219:PLK4 protein, human