Binding Site

Inositol monophosphatase, metal-binding site (IPR020583)

Short name: Inositol_monoP_metal-BS


It has been shown that several proteins share two sequence motifs [PMID: 1660408]. Two of these proteins, vertebrate and plant inositol monophosphatase (EC:, and vertebrate inositol polyphosphate 1-phosphatase (EC:, are enzymes of the inositol phosphate second messenger signalling pathway, and share similar enzyme activity. Both enzymes exhibit an absolute requirement for metal ions (Mg2+ is preferred), and their amino acid sequences contain a number of conserved motifs, which are also shared by several other proteins related to MPTASE (including products of fungal QaX and qutG, bacterial suhB and cysQ, and yeast hal2) [PMID: 7761465]. The function of the other proteins is not yet clear, but it is suggested that they may act by enhancing the synthesis or degradation of phosphorylated messenger molecules [PMID: 1660408]. Structural analysis of these proteins has revealed a common core of 155 residues, which includes residues essential for metal binding and catalysis. An interesting property of the enzymes of this family is their sensitivity to Li+. The targets and mechanism of action of Li+ are unknown, but overactive inositol phosphate signalling may account for symptoms of manic depression [PMID: 2553271].

This entry represents the metal-binding site found within the inositol monophosphatase family of proteins. It is suggested [PMID: 1660408] that these proteins may act by enhancing the synthesis or degradation of phosphorylated messenger molecules. The signature pattern of this entry contains the aspartic and threonine residues involved in binding a metal ion [PMID: 1332026].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE patterns