EC Number   |
General Information |
Reference |
|---|
   3.1.3.56 | evolution |
enzyme Siw14 is a member of the protein tyrosine-phosphatase (PTP) superfamily. Siw14 has a cysteine-based, class I CX5R(S/T) motif that defines the family of protein-tyrosine phosphatases (PTPs). Bioinformatic studies lead to Siw14 being classified as belonging within a specialist subgroup of PTPs, the dual specific protein-tyrosine phosphatases (DUSPs). The DUSPs themselves include a distinct class of proteins that appears not to have substantial activity against phosphoproteins. These are usually described as nonprotein-specific or atypical phosphatases. The inclusion of Siw14 in this category is supported by biochemical analysis, the enzyme's catalytic activity against 5-diphosphoinositol 1,2,3,4,6-pentakisphosphate (5-InsP7) is several orders of magnitude greater than that against 4-nitrophenyl phosphate, a generic protein phosphatase substrate. Other members of this atypical DUSP subgroup preferentially hydrolyze either phosphorylated carbohydrates, inositol lipids, or triphosphate groups in mRNA. Thus, this DUSP subfamily exhibits catalytic site diversity that is not observed for classical PTPs |
-, 751120 |
| 3.1.3.56 | evolution |
phylogenetic analyses are performed to delineate the evolutionary history of the polyphosphate 5-phosphatase family in major angiosperm lineages |
771726 |
| 3.1.3.56 | malfunction |
mutations in INPP5K have been detected in patients with a rare form of autosomal recessive congenital muscular dystrophy with cataract, short stature and intellectual disability |
768412 |
| 3.1.3.56 | malfunction |
the increase in the levels of 1D-myo-inositol 1,4,5-trisphosphate/Ca2+ caused by deficiency of inositol polyphosphate 5-phosphatases is sufficient to break pollen dormancy and to trigger early germination |
729621 |
| 3.1.3.56 | malfunction |
transgenic tobacco plants overexpressing Le5PT1 exhibit reduced growth in height, leaf area, and dry weight compared to wild type plants. The transgenic plants have lower water use efficiency than wild type and the downregulation of the drought-responsive gene, NtERD10B |
-, 768111 |
| 3.1.3.56 | metabolism |
inositol pyrophosphate metabolism in Saccharomyces cerevisiae involving enzyme Siw14, overview |
-, 751120 |
| 3.1.3.56 | more |
active site architecture and substrate binding pocket structure, overview. The core catalytic domain of Siw14 is formed by residues 116-281. The three structural elements that demarcate a 9.2-A-deep substrate-binding pocket each have spatial equivalents in PTPs, but these are specialized for Siw14 to bind and hydrolyze the intensely negatively charged diphosphoinositol phosphates. A loop between the alpha5 and alpha6 helices, corresponding to the Q-loop in PTPs, contains a lysine and an arginine that extend into the catalytic pocket due to displacement of the alpha5 helix orientation through intramolecular crowding caused by three bulky, hydrophobic residues. The general-acid loop in PTPs is replaced in Siw14 with a flexible loop that does not use an aspartate or glutamate as a general acid |
-, 751120 |
| 3.1.3.56 | physiological function |
alters abscisic acid and light signaling, stomatal opening, seedling development |
772168 |
| 3.1.3.56 | physiological function |
alters abscisic acid signaling, seedling development |
772168 |
| 3.1.3.56 | physiological function |
cotyledon vein development, alters auxin, abscisic acid, sugar and PHOTOTROPIN1 signaling, root gravitropism, vesicle trafficking |
772168 |
