Summary: Myo-inositol-1-phosphate synthase
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Inositol-3-phosphate synthase Edit Wikipedia article
|PDB structures||RCSB PDB PDBe PDBsum|
|Gene Ontology||AmiGO / QuickGO|
myo-inositol phosphate synthase mips from a. fulgidus
|SCOPe||1gr0 / SUPFAM|
- D-glucose 6-phosphate 1D-myo-inositol 3-phosphate
This enzyme belongs to the family of isomerases, specifically the class of intramolecular lyases. The systematic name of this enzyme class is 1D-myo-inositol-3-phosphate lyase (isomerizing). Other names in common use include myo-inositol-1-phosphate synthase, D-glucose 6-phosphate cycloaldolase, inositol 1-phosphate synthatase, glucose 6-phosphate cyclase, inositol 1-phosphate synthetase, glucose-6-phosphate inositol monophosphate cycloaldolase, glucocycloaldolase, and 1L-myo-inositol-1-phosphate lyase (isomerizing).
This enzyme participates in streptomycin biosynthesis and inositol phosphate metabolism. It employs one cofactor, NAD+. The reaction this enzyme catalyses represents the first committed step in the production of all inositol-containing compounds, including phospholipids, either directly or by salvage. The enzyme exists in a cytoplasmic form in a wide range of plants, animals, and fungi. It has also been detected in several bacteria and a chloroplast form is observed in alga and higher plants. Inositol phosphates play an important role in signal transduction.
In Saccharomyces cerevisiae (Baker's yeast), the transcriptional regulation of the INO1 gene encoding inositol-3-phosphate synthase has been studied in detail and its expression is sensitive to the availability of phospholipid precursors as well as growth phase. The regulation of the structural gene encoding 1L-myo-inositol-1-phosphate synthase has also been analyzed at the transcriptional level in the aquatic angiosperm, Spirodela polyrrhiza (Giant duckweed) and the halophyte, Mesembryanthemum crystallinum (Common ice plant).
In prokaryotes, myo-D-inositol phosphate synthase was discovered by Bachhawat and Mande in 1999 (reported in Journal of Molecular Biology). The existence of inositol in prokaryotes is not extensive, but the discovery of this enzyme first in Mycobacterium tuberculosis, nucleated activity towards finding its inhibitors.
- Klig LS, Zobel PA, Devry CG, Losberger C (June 1994). "Comparison of INO1 gene sequences and products in Candida albicans and Saccharomyces cerevisiae". Yeast. 10 (6): 789â€“800. doi:10.1002/yea.320100609. PMID 7975896.
- Majumder AL, Johnson MD, Henry SA (September 1997). "1L-myo-inositol-1-phosphate synthase". Biochim. Biophys. Acta. 1348 (1â€“2): 245â€“56. doi:10.1016/s0005-2760(97)00122-7. PMID 9370339.
- Eisenberg F Jr (1967). "D-myoinositol 1-phosphate as product of cyclization of glucose 6-phosphate and substrate for a specific phosphatase in rat testis". J. Biol. Chem. 242 (7): 1375â€“82. PMID 4290245.
- Sherman WR, Stewart MA, Zinbo M (1969). "Mass spectrometric study on the mechanism of D-glucose 6-phosphate-L-myo-inositol 1-phosphate cyclase". J. Biol. Chem. 244 (20): 5703â€“8. PMID 4310603.
- Barnett JE, Corina DL (1968). "The mechanism of glucose 6-phosphate-D-myo-inositol 1-phosphate cyclase of rat testis. The involvement of hydrogen atoms". Biochem. J. 108 (1): 125â€“9. PMC 1198777. PMID 4297937.
- Barnett JE, Rasheed A, Corina DL (1973). "Partial reactions of D-glucose 6-phosphate-1L-myoinositiol 1-phosphate cyclase". Biochem. J. 131 (1): 21â€“30. PMC 1177435. PMID 4352864.
Bachhawat N and Mande SC (1999) J. Mol. Biol. Identification of the INO1 gene of Mycobacterium tuberculosis H37Rv reveals a novel class of inositol-1-phosphate synthase enzyme. 291, 531-536.
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Myo-inositol-1-phosphate synthase Provide feedback
This is a family of myo-inositol-1-phosphate synthases. Inositol-1-phosphate catalyses the conversion of glucose-6- phosphate to inositol-1-phosphate, which is then dephosphorylated to inositol . Inositol phosphates play an important role in signal transduction.
Internal database links
|Similarity to PfamA using HHSearch:||NAD_binding_5|
External database links
This tab holds annotation information from the InterPro database.
InterPro entry IPR013021
This is a region of myo-inositol-1-phosphate synthases that is related to the glyceraldehyde-3-phosphate dehydrogenase-like, C-terminal domain.
1L-myo-Inositol-1-phosphate synthase ( EC ) catalyzes the conversion of D-glucose 6-phosphate to 1L-myo-inositol-1-phosphate, the first committed step in the production of all inositol-containing compounds, including phospholipids, either directly or by salvage. The enzyme exists in a cytoplasmic form in a wide range of plants, animals, and fungi. It has also been detected in several bacteria and a chloroplast form is observed in alga and higher plants. Inositol phosphates play an important role in signal transduction.
In Saccharomyces cerevisiae (Baker's yeast), the transcriptional regulation of the INO1 gene has been studied in detail [ PUBMED:7975896 ] and its expression is sensitive to the availability of phospholipid precursors as well as growth phase. The regulation of the structural gene encoding 1L-myo-inositol-1-phosphate synthase has also been analyzed at the transcriptional level in the aquatic angiosperm, Spirodela polyrrhiza (Giant duckweed) and the halophyte, Mesembryanthemum crystallinum (Common ice plant) [ PUBMED:9370339 ].
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This clan contains the C terminal domains of dehydrogenase enzymes involved in the biosynthesis of arginine, aspartate and aspartate derived amino acids. It also contains the C terminal domain of GAPDH, a dehydrogenase involved in glycolysis and gluconeogenesis.
The clan contains the following 18 members:AcetDehyd-dimer Asp_DH_C Biliv-reduc_cat DapB_C DAPDH_C DXP_redisom_C G6PD_C GFO_IDH_MocA_C GFO_IDH_MocA_C2 Gp_dh_C Homoserine_dh Inos-1-P_synth OpcA_G6PD_C ox_reductase_C Oxidoreduct_C OxRdtase_C Sacchrp_dh_C Semialdhyde_dhC
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|Seed source:||Pfam-B_959 (release 4.1)|
|Author:||Bashton M , Bateman A|
|Number in seed:||121|
|Number in full:||4478|
|Average length of the domain:||111.00 aa|
|Average identity of full alignment:||40 %|
|Average coverage of the sequence by the domain:||25.25 %|
|HMM build commands:||
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 61295632 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||20|
|Download:||download the raw HMM for this family|
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For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the Inos-1-P_synth domain has been found. There are 38 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein sequence.
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AlphaFold Structure Predictions
The list of proteins below match this family and have AlphaFold predicted structures. Click on the protein accession to view the predicted structure.