A Structural Comparison of Inhibitor Binding to Pkb, Pka and Pka-Pkb ChimeraDavies, T.G., Verdonk, M.L., Graham, B., Saalau-Bethell, S., Hamlett, C.C.F., Mchardy, T., Collins, I., Garrett, M.D., Workman, P., Woodhead, S.J., Jhoti, H., Barford, D.
(2007) J Mol Biol 367: 882
- PubMed: 17275837
- DOI: https://doi.org/10.1016/j.jmb.2007.01.004
- Primary Citation of Related Structures:
2JDO, 2JDR, 2JDS, 2JDT, 2JDV
- PubMed Abstract:
Although the crystal structure of the anti-cancer target protein kinase B (PKBbeta/Akt-2) has been useful in guiding inhibitor design, the closely related kinase PKA has generally been used as a structural mimic due to its facile crystallization with a range of ligands. The use of PKB-inhibitor crystallography would bring important benefits, including a more rigorous understanding of factors dictating PKA/PKB selectivity, and the opportunity to validate the utility of PKA-based surrogates. We present a "back-soaking" method for obtaining PKBbeta-ligand crystal structures, and provide a structural comparison of inhibitor binding to PKB, PKA, and PKA-PKB chimera. One inhibitor presented here exhibits no PKB/PKA selectivity, and the compound adopts a similar binding mode in all three systems. By contrast, the PKB-selective inhibitor A-443654 adopts a conformation in PKB and PKA-PKB that differs from that with PKA. We provide a structural explanation for this difference, and highlight the ability of PKA-PKB to mimic the true PKB binding mode in this case.
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