1g0h
From Proteopedia
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CRYSTAL STRUCTURE OF MJ0109 GENE PRODUCT INOSITOL MONOPHOSPHATASE-FRUCTOSE 1,6 BISPHOSPHATASE
Overview
Inositol monophosphatase (EC 3.1.3.25) in hyperthermophilic archaea is thought to play a role in the biosynthesis of di-myo-inositol-1,1'-phosphate (DIP), an osmolyte unique to hyperthermophiles. The Methanococcus jannaschii MJ109 gene product, the sequence of which is substantially homologous to that of human inositol monophosphatase, exhibits inositol monophosphatase activity but with substrate specificity that is broader than those of bacterial and eukaryotic inositol monophosphatases (it can also act as a fructose bisphosphatase). To understand its substrate specificity as well as the poor inhibition by Li(+) (a potent inhibitor of the mammalian enzyme), we have crystallized the enzyme and determined its three-dimensional structure. The overall fold, as expected, is similar to that of the mammalian enzyme, but the details suggest a closer relationship to fructose 1,6-bisphosphatases. Three complexes of the MJ0109 protein with substrate and/or product and inhibitory as well as activating metal ions suggest that the phosphatase mechanism is a three-metal ion assisted catalysis which is in variance with that proposed previously for the human inositol monophosphatase.
About this Structure
1G0H is a Single protein structure of sequence from Methanocaldococcus jannaschii with and as ligands. Active as Inositol-phosphate phosphatase, with EC number 3.1.3.25 Full crystallographic information is available from OCA.
Reference
Crystal structure and catalytic mechanism of the MJ0109 gene product: a bifunctional enzyme with inositol monophosphatase and fructose 1,6-bisphosphatase activities., Johnson KA, Chen L, Yang H, Roberts MF, Stec B, Biochemistry. 2001 Jan 23;40(3):618-30. PMID:11170378
Page seeded by OCA on Thu Feb 21 12:44:41 2008
