Cloned (Comment) | Organism |
---|---|
gene GWD1, construction of transgenic plants expressing the soluble StrepII-tagged mutant enzyme, transformation via Agrobacterium tumefaciens mediation method | Arabidopsis thaliana |
Protein Variants | Comment | Organism |
---|---|---|
additional information | construction of transgenic Arabidopsis thaliana plants, i.e. gwd-c1, gwd-c2, and gwd-c1/gwd-c2 or sex1-8, with reduced or no GWD activity. Absence of GWD results in altered starch granule morphology but no change in the physicochemical properties of starch granules, phenotype, overview. Partially complemented GWD transgenic lines exhibit an intermediate phenotype. Effects of the mutations on starch-related enzymes in the four Arabidopsis lines, overview | Arabidopsis thaliana |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
chloroplast | - |
Arabidopsis thaliana | 9507 | - |
starch granule | altered GWD expression levels influence the surface properties of starch granules, determination of granule morphologies in different transgenic lines, which affects the starch synthesis by enzyme AtSS1, overview | Arabidopsis thaliana | - |
- |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mg2+ | required | Arabidopsis thaliana |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
160000 | - |
recombinant StrepII-tagged enzyme | Arabidopsis thaliana |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + alpha-glucan + H2O | Arabidopsis thaliana | - |
AMP + phospho-alpha-glucan + phosphate | - |
? | |
additional information | Arabidopsis thaliana | the activity of GWD correlates with the amount of accessible glucan chains on the starch granule surface | ? | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Arabidopsis thaliana | Q9SAC6 | - |
- |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
leaf | - |
Arabidopsis thaliana | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + alpha-glucan + H2O | - |
Arabidopsis thaliana | AMP + phospho-alpha-glucan + phosphate | - |
? | |
additional information | the activity of GWD correlates with the amount of accessible glucan chains on the starch granule surface | Arabidopsis thaliana | ? | - |
? |
Synonyms | Comment | Organism |
---|---|---|
At1g10760 | locus name | Arabidopsis thaliana |
glucan, water dikinase | - |
Arabidopsis thaliana |
GWD | - |
Arabidopsis thaliana |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
30 | - |
assay at | Arabidopsis thaliana |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.4 | - |
assay at | Arabidopsis thaliana |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
ATP | - |
Arabidopsis thaliana |
General Information | Comment | Organism |
---|---|---|
malfunction | GWD-deficient Arabidopsis thaliana mutants have a starch excess phenotype (sex1). The internal structure of granules isolated from GWD mutant plants, having reduced or no GWD activity, is unaffected, as thermal stability, allomorph, chain length distribution and density of starch granules are similar to wild-type, but short glucan chain residues located at the granule surface dominate in starches of transgenic plants and impede GWD activity. A similarly reduced rate of phosphorylation by GWD is also observed in potato tuber starch fractions that differ in the proportion of accessible glucan chain residues at the granule surface. A model is proposed to explain the characteristic morphology of starch granules observed in GWD transgenic plants. The model postulates that the occupancy rate of single glucan chains at the granule surface limits accessibility to starch-related enzymes | Arabidopsis thaliana |
metabolism | glucan, water dikinase is a key enzyme of starch metabolism | Arabidopsis thaliana |
physiological function | phosphorylation of transitory starch by alpha-glucan, water dikinase during starch turnover affects the surface properties and morphology of starch granules | Arabidopsis thaliana |