Structural Basis of Constitutive Activity and a Unique Nucleotide Binding Mode of Human Pim-1 Kinase.Qian, K.C., Wang, L., Hickey, E.R., Studts, J., Barringer, K., Peng, C., Kronkaitis, A., Li, J., White, A., Mische, S., Farmer, B.
(2005) J.Biol.Chem. 280: 6130-6137
- PubMed: 15525646
- DOI: 10.1074/jbc.M409123200
- Primary Citation of Related Structures:  1XR1
- PubMed Abstract:
Pim-1 kinase is a member of a distinct class of serine/threonine kinases consisting of Pim-1, Pim-2, and Pim-3. Pim kinases are highly homologous to one another and share a unique consensus hinge region sequence, ER-PXPX, with its two proline residue ...
Pim-1 kinase is a member of a distinct class of serine/threonine kinases consisting of Pim-1, Pim-2, and Pim-3. Pim kinases are highly homologous to one another and share a unique consensus hinge region sequence, ER-PXPX, with its two proline residues separated by a non-conserved residue, but they (Pim kinases) have <30% sequence identity with other kinases. Pim-1 has been implicated in both cytokine-induced signal transduction and the development of lymphoid malignancies. We have determined the crystal structures of apo Pim-1 kinase and its AMP-PNP (5'-adenylyl-beta,gamma-imidodiphosphate) complex to 2.1-angstroms resolutions. The structures reveal the following. 1) The kinase adopts a constitutively active conformation, and extensive hydrophobic and hydrogen bond interactions between the activation loop and the catalytic loop might be the structural basis for maintaining such a conformation. 2) The hinge region has a novel architecture and hydrogen-bonding pattern, which not only expand the ATP pocket but also serve to establish unambiguously the alignment of the Pim-1 hinge region with that of other kinases. 3) The binding mode of AMP-PNP to Pim-1 kinase is unique and does not involve a critical hinge region hydrogen bond interaction. Analysis of the reported Pim-1 kinase-domain structures leads to a hypothesis as to how Pim kinase activity might be regulated in vivo.
Departments of Medicinal Chemistry and Immunology and Inflammation, Boehringer Ingelheim Pharmaceuticals, Inc., Research and Development, 175 Briar Ridge Rd., Ridgefield, CT 06877, USA.