Structure of the Catalytic Domain of Human Polo-like Kinase 1

详细信息    查看全文

• 作者：Michael Kothe ; Darcy Kohls ; Simon Low ; Rocco Coli ; Alan C. Cheng ; Suzanne L. Jacques ; Theresa L. Johnson ; Cristina Lewis ; Christine Loh ; Jim Nonomiya ; Alissa L. Sheils ; Kimberly A. Verdries ; Thomas A.
• 刊名：Biochemistry
• 出版年：2007
• 出版时间：May 22, 2007
• 年：2007
• 卷：46
• 期：20
• 页码：5960 - 5971
• 全文大小：1207K
• 年卷期：v.46,no.20(May 22, 2007)
• ISSN：1520-4995

文摘

Polo-like kinase 1 (Plk1) is an attractive target for the development of anticancer agents dueto its importance in regulating cell-cycle progression. Overexpression of Plk1 has been detected in avariety of cancers, and expression levels often correlate with poor prognosis. Despite high interest inPlk1-targeted therapeutics, there is currently no structure publicly available to guide structure-based drugdesign of specific inhibitors. We determined the crystal structures of the T210V mutant of the kinasedomain of human Plk1 complexed with the nonhydrolyzable ATP analogue adenylylimidodiphosphate(AMPPNP) or the pyrrolo-pyrazole inhibitor PHA-680626 at 2.4 and 2.1 Å resolution, respectively.Plk1 adopts the typical kinase domain fold and crystallized in a conformation resembling the activestate of other kinases. Comparison of the kinetic parameters determined for the (unphosphorylated)wild-type enzyme, as well as the T210V and T210D mutants, shows that the mutations primarily affectthe k_cat of the reaction, with little change in the apparent K_m for the protein or nucleotide substrates (k_cat= 0.0094, 0.0376, and 0.0049 s^-1 and K_m(ATP) = 3.2, 4.0, and 3.0 M for WT, T210D, and T210V,respectively). The structure highlights features of the active site that can be exploited to obtain Plk1-specific inhibitors with selectivity over other kinases and Plk isoforms. These include the presence of aphenylalanine at the bottom of the ATP pocket, combined with a cysteine (as opposed to the morecommonly found leucine) in the roof of the binding site, a pocket created by Leu132 in the hinge region,and a cluster of positively charged residues in the solvent-exposed area outside of the adenine pocketadjacent to the hinge region.