EC Number   |
General Information |
Reference |
|---|
   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 |
| 3.1.3.56 | physiological function |
divergent functions of polyphosphate 5-phosphatase genes, allowing the angiosperms to successfully adapt to a great number of ecological niches |
771726 |
| 3.1.3.56 | physiological function |
downregulation of INPP5K disrupts muscle fiber morphology and results in abnormal eye development |
749530 |
| 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 | physiological function |
Gs5PTase8 plays a positive role in salt tolerance and might be a candidate gene for improving soybean adaptation to salt stress. Ectopic expression of Gs5PTase8 enhances salt tolerance in plants |
772178 |
| 3.1.3.56 | metabolism |
inositol pyrophosphate metabolism in Saccharomyces cerevisiae involving enzyme Siw14, overview |
-, 751120 |
| 3.1.3.56 | physiological function |
INPP5K functions extend from control of insulin signaling, endoplasmic reticulum stress response and structural integrity, myoblast differentiation, cytoskeleton organization, cell adhesion and migration, renal osmoregulation, to cancer |
768412 |
