3MOZ

Structure of the PTP-like phytase from Selenomonas ruminantium in complex with myo-inositol (1,2,3,5,6)pentakisphosphate

Summary for 3MOZ

• Entry DOI: 10.2210/pdb3moz/pdb
• Related: 2B4U 3MMJ
• Descriptor: Myo-inositol hexaphosphate phosphohydrolase, PHOSPHATE ION, (1R,2R,3R,4R,5S,6S)-6-HYDROXYCYCLOHEXANE-1,2,3,4,5-PENTAYL PENTAKIS[DIHYDROGEN (PHOSPHATE)], ... (7 entities in total)
• Functional Keywords: phytase, protein tyrosine phosphatase, inositol phosphatase, inositol phosphate, hydrolase
• Biological source: Selenomonas ruminantium
• Total number of polymer chains: 2
• Total formula weight: 74705.36

Authors

Gruninger, R.J.,Selinger, L.B.,Mosimann, S.C. (deposition date: 2010-04-23, release date: 2011-06-22, Last modification date: 2023-09-06)

Primary citation

Gruninger, R.J.,Dobing, S.,Smith, A.D.,Bruder, L.M.,Selinger, L.B.,Wieden, H.J.,Mosimann, S.C.
Substrate binding in protein-tyrosine phosphatase-like inositol polyphosphatases.
J.Biol.Chem., 287:9722-9730, 2012

PubMed Abstract: Protein-tyrosine phosphatase-like inositol polyphosphatases are microbial enzymes that catalyze the stepwise removal of one or more phosphates from highly phosphorylated myo-inositols via a relatively ordered pathway. To understand the substrate specificity and kinetic mechanism of these enzymes we have determined high resolution, single crystal, x-ray crystallographic structures of inactive Selenomonas ruminantium PhyA in complex with myo-inositol hexa- and pentakisphosphate. These structures provide the first glimpse of a myo-inositol polyphosphatase-ligand complex consistent with its known specificity and reveal novel features of the kinetic mechanism. To complement the structural studies, fluorescent binding assays have been developed and demonstrate that the K(d) for this enzyme is several orders of magnitude lower than the K(m). Together with rapid kinetics data, these results suggest that the protein tyrosine phosphatase-like inositol polyphosphatases have a two-step, substrate-binding mechanism that facilitates catalysis.

PubMed: 22139834
DOI: 10.1074/jbc.M111.309872

Experimental method

X-RAY DIFFRACTION (1.6 Å)