Kinase Family IPK
Kinase Classification: Group PKL: Family IPK
A set of 3 subfamilies that further phosphorylate inositol phosphates, and have structures intermediate between PKL and ATP-Grasp folds. These have primary sequence similarity to each other.
The IPK family has the following subfamilies:
IP3K
Inositol-trisphosphate 3-kinase
IP6K
Inositol hexaphosphate kinase
IPMK
Inositol polyphosphate multikinase
Kinase Domain
The IPK kinase domain is related to the PIPK family. SCOP classifies both families in the SAICAR synthase-like superfamily with similarity to both the PKL and the ATP-Grasp folds. In both families, the N-lobe is closer to PKL while the C-lobe is more related to ATP-Grasp. This similarity was first predicted by deep sequence comparison [1] and confirmed by a crystal structures [2, 3, 4, 5]. The K72, D166 and D184 catalytic residues of PKLs are well conserved in most IPK [1].
Evolution
The family is found in most eukaryotes.
References
- Cheek S, Ginalski K, Zhang H, and Grishin NV. A comprehensive update of the sequence and structure classification of kinases. BMC Struct Biol. 2005 Mar 16;5:6. DOI:10.1186/1472-6807-5-6 |
- Miller GJ and Hurley JH. Crystal structure of the catalytic core of inositol 1,4,5-trisphosphate 3-kinase. Mol Cell. 2004 Sep 10;15(5):703-11. DOI:10.1016/j.molcel.2004.08.005 |
- Takazawa K, Perret J, Dumont JE, and Erneux C. Molecular cloning and expression of a human brain inositol 1,4,5-trisphosphate 3-kinase. Biochem Biophys Res Commun. 1991 Jan 31;174(2):529-35. DOI:10.1016/0006-291x(91)91449-m |
- González B, Schell MJ, Letcher AJ, Veprintsev DB, Irvine RF, and Williams RL. Structure of a human inositol 1,4,5-trisphosphate 3-kinase: substrate binding reveals why it is not a phosphoinositide 3-kinase. Mol Cell. 2004 Sep 10;15(5):689-701. DOI:10.1016/j.molcel.2004.08.004 |
- Holmes W and Jogl G. Crystal structure of inositol phosphate multikinase 2 and implications for substrate specificity. J Biol Chem. 2006 Dec 8;281(49):38109-16. DOI:10.1074/jbc.M606883200 |
