Activating Compound | Comment | Organism | Structure |
---|---|---|---|
microtubules | SPAS-1's ATPase activity increases with increasing concentrations of microtubules up to 0.00025 mM and then declines at higher microtubule concentrations. In the presence of 0.00025 mM microtubules, ATPase activity is 7times higher than in the absence of microtubules | Caenorhabditis elegans |
Cloned (Comment) | Organism |
---|---|
SPAS-1 protein (451 amino acid reisdues) is produced as an N-terminally His6-tagged recombinant protein, expressed in Escherichia coli BL21(DE3) | Caenorhabditis elegans |
Crystallization (Comment) | Organism |
---|---|
secondary structure analyzed by circular dichroism (CD) spectrum. SPAS-1 retains a high degree of alpha-helical structure | Caenorhabditis elegans |
Protein Variants | Comment | Organism |
---|---|---|
E278Q | Walker B mutant SPAS-1, abolished ATPase activity | Caenorhabditis elegans |
K224R | Walker A mutant SPAS-1, abolished ATPase activity | Caenorhabditis elegans |
K257A | exhibits 130% of wild-type ATPase activity | Caenorhabditis elegans |
additional information | mutational analysis reveals that the conserved exposed, basic amino acid residues in the pore region of stastin as well as the aromatic residue are important for the recognition and severing of microtubules. The conformational change of W251 is detected upon ATP binding by measuring the fluorescence emission spectra of tryptophan. Given that K257 is located close to the corresponding aromatic residue W251, it seems possible that K257 is also involved in a mechanochemical process from conformational change of W251 in microtubule severing | Caenorhabditis elegans |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
1.53 | - |
ATP | 37°C, pH 8.8, Vmax: 115 nmol/microg/min | Caenorhabditis elegans |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
soluble | mostly in the soluble fraction after ultracentrifugation | Caenorhabditis elegans | - |
- |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
52000 | - |
1 * 52000, SDS-PAGE, when low concentrations of SPAS-1 (below 0.55 mg/ml) are analyzed, stable hexamers are not formed, rather it shows a broad elution profile over monomer to hexamer, even in the presence of ATP | Caenorhabditis elegans |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Caenorhabditis elegans | - |
- |
- |
Purification (Comment) | Organism |
---|---|
90% pure after Ni2+-NTA agarose, analyzed by SDS-PAGE | Caenorhabditis elegans |
Source Tissue | Comment | Organism | Textmining |
---|
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
0.07 | - |
37°C, pH 8.8 | Caenorhabditis elegans |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + H2O | - |
Caenorhabditis elegans | ADP + phosphate | - |
? |
Subunits | Comment | Organism |
---|---|---|
hexamer | SPAS-1 forms a stable hexamer in a concentration-dependent manner. The microtubule binding domain MTBD of SPAS-1 plays a critical role in enrichment of SPAS-1 to microtubules, where SPAS-1 is concentrated above 5 mg/ml and able to form a stable hexamer. Hexamer formation takes place in an ATP-independent manner | Caenorhabditis elegans |
monomer | 1 * 52000, SDS-PAGE, when low concentrations of SPAS-1 (below 0.55 mg/ml) are analyzed, stable hexamers are not formed, rather it shows a broad elution profile over monomer to hexamer, even in the presence of ATP | Caenorhabditis elegans |
Synonyms | Comment | Organism |
---|---|---|
SPAS-1 | spastin homologue | Caenorhabditis elegans |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Caenorhabditis elegans |
Temperature Stability Minimum [°C] | Temperature Stability Maximum [°C] | Comment | Organism |
---|---|---|---|
47 | - |
the melting temperature Tm is estimated from the denaturation curve | Caenorhabditis elegans |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
8.8 | - |
assay at | Caenorhabditis elegans |
General Information | Comment | Organism |
---|---|---|
physiological function | SPAS-1 shows microtubule-severing activity when expresses in cultured cells. When alpha/beta tubulin dimer is incubated with SPAS-1, tubulin is pulled down with SPAS-1, suggesting the Caenorhabditis elegans SPAS-1 binds to tubulin | Caenorhabditis elegans |