From Proteopedia

---

Revision as of 05:05, 21 November 2007

proteopedia linkproteopedia link

spinqualitylabelsall models 1z2o, resolution 1.24Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Inositol 1,3,4-trisphosphate 5/6-Kinase in complex with mg2+/ADP/Ins(1,3,4,6)P4

Overview

Inositol hexakisphosphate and other inositol high polyphosphates have, diverse and critical roles in eukaryotic regulatory pathways. Inositol, 1,3,4-trisphosphate 5/6-kinase catalyzes the rate-limiting step in, inositol high polyphosphate synthesis in animals. This multifunctional, enzyme also has inositol 3,4,5,6-tetrakisphosphate 1-kinase and other, activities. The structure of an archetypal family member, from Entamoeba, histolytica, has been determined to 1.2 A resolution in binary and ternary, complexes with nucleotide, substrate, and product. The structure reveals, an ATP-grasp fold. The inositol ring faces ATP edge-on such that the 5-, and 6-hydroxyl groups are nearly equidistant from the ATP gamma-phosphate, in catalytically productive phosphoacceptor positions and explains the, unusual dual site specificity of this kinase. Inositol tris- and, tetrakisphosphates interact via three phosphate binding subsites and one, solvent-exposed site that could in principle be occupied by 18 different, substrates, explaining the mechanisms for the multiple specificities and, catalytic activities of this enzyme.

About this Structure

1Z2O is a Single protein structure of sequence from Eukaryota with MG, ADP and I4P as ligands. Full crystallographic information is available from OCA.

Reference

Specificity determinants in inositol polyphosphate synthesis: crystal structure of inositol 1,3,4-trisphosphate 5/6-kinase., Miller GJ, Wilson MP, Majerus PW, Hurley JH, Mol Cell. 2005 Apr 15;18(2):201-12. PMID:15837423

Page seeded by OCA on Wed Nov 21 07:12:41 2007