Any feedback?
Please rate this page
(literature.php)
(0/150)

BRENDA support

Literature summary extracted from

  • Li, Z.; Stieglitz, K.; Shrout, A.; Wei, Y.; Weis, R.; Stec, B.; Roberts, M.
    Mobile loop mutations in an archaeal inositol monophosphatase: Modulating three-metal ion assisted catalysis and lithium inhibition (2010), Protein Sci., 19, 309-318.
    View publication on PubMedView publication on EuropePMC

Crystallization (Commentary)

EC Number Crystallization (Comment) Organism
3.1.3.25 MJ0109 with bound metal ions, Mg2+, Zn2+, or Mn2+, crystal structure analysis, PDB ID 1DK4 Methanocaldococcus jannaschii

Protein Variants

EC Number Protein Variants Comment Organism
3.1.3.25 D26A site-directed mutagenesis, the mutant shows no significant change in the Mg2+ requirement for optimal activity Methanocaldococcus jannaschii
3.1.3.25 D38A site-directed mutagenesis, the mutant shows an increased Km for Mg2+, but little effect on kcat compared to the wild-type enzyme, the mutant has a dramatically enhanced sensitivity to Li+ compared to the wild-type, with an IC50 of 12 mM. Electron density map for MJ0109 D38A mobile loop and active site with and without bound Li+, overview Methanocaldococcus jannaschii
3.1.3.25 E39A site-directed mutagenesis, the mutant shows no significant change in the Mg2+ requirement for optimal activity Methanocaldococcus jannaschii
3.1.3.25 E41A site-directed mutagenesis, the mutant shows no significant change in the Mg2+ requirement for optimal activity Methanocaldococcus jannaschii

Inhibitors

EC Number Inhibitors Comment Organism Structure
3.1.3.25 Ca2+
-
 Methanocaldococcus jannaschii
3.1.3.25 Li+ specific mode of action for lithium inhibition in the IMPase superfamily, lithium ion inhibition of the archaeal IMPase is very poor with an IC50 of about 250 mM, mutant D38A enzyme has a dramatically enhanced sensitivity to Li+ with an IC50 of 12 mM Methanocaldococcus jannaschii
3.1.3.25 Mg2+ tight binding of Mg2+ to the protein affects the secondary structure Methanocaldococcus jannaschii

Metals/Ions

EC Number Metals/Ions Comment Organism Structure
3.1.3.25 Mg2+ the enzyme requires 5-10 mM Mg21 for optimum catalysis, three to four ions are tightly bound in the absence of ligands. Asp38 coordinates the third metal ion in the substrate complex, but with sufficient flexibility in the loop such that other acidic residues can position the Mg2+ in the active site in the absence of Asp38. Thermodynamic parameters for Mg2+ binding, overview Methanocaldococcus jannaschii
3.1.3.25 additional information metal coordination and binding structures of MJ0109, metal 1 is coordinated by Asp84, Asp201, and two phosphate oxygens from substrate or product in a tetrahedral conformation. Metal 2 is coordinated by Asp84, Asp81, Glu65, a phosphate oxygen, and a water molecule. Metal 3 binding involves Asp38, detailed overview Methanocaldococcus jannaschii

Natural Substrates/ Products (Substrates)

EC Number Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
3.1.3.25 myo-inositol 1-phosphate + H2O Methanocaldococcus jannaschii
-
 myo-inositol + phosphate
-
 ?

Organism

EC Number Organism UniProt Comment Textmining
3.1.3.25 Methanocaldococcus jannaschii
-
-
-

Substrates and Products (Substrate)

EC Number Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
3.1.3.25 myo-inositol 1-phosphate + H2O
-
 Methanocaldococcus jannaschii myo-inositol + phosphate
-
 ?

Synonyms

EC Number Synonyms Comment Organism
3.1.3.25 IMPase
-
 Methanocaldococcus jannaschii
3.1.3.25 inositol monophosphatase
-
 Methanocaldococcus jannaschii
3.1.3.25 MJ0109
-
 Methanocaldococcus jannaschii

Temperature Optimum [°C]

EC Number Temperature Optimum [°C] Temperature Optimum Maximum [°C] Comment Organism
3.1.3.25 85
-
 assay at Methanocaldococcus jannaschii

Temperature Stability [°C]

EC Number Temperature Stability Minimum [°C] Temperature Stability Maximum [°C] Comment Organism
3.1.3.25 additional information
-
 the archaeal IMPase is extremely stable and active over a wide temperature range Methanocaldococcus jannaschii

IC50 Value

EC Number IC50 Value IC50 Value Maximum Comment Organism Inhibitor Structure
3.1.3.25 12
-
 mutant D38A, pH not specified in the publication, 85°C Methanocaldococcus jannaschii Li+
3.1.3.25 240
-
 wild-type enzyme, pH not specified in the publication, 85°C Methanocaldococcus jannaschii Li+