Activating Compound | Comment | Organism | Structure |
---|---|---|---|
additional information | a peptide ligand, which copurifies and cocrystallizes with CtpB, is observed at the entrance of the protease tunnel near the catalytic triad, its binding to the PDZ domain stimulates the protease activity | Bacillus subtilis |
Cloned (Comment) | Organism |
---|---|
expression of the His-tagged enzyme in Escherichia coli strains BL21(DE3)pLysS or B834(DE3) | Bacillus subtilis |
Crystallization (Comment) | Organism |
---|---|
purified recombinant enzyme, all CtpB crystals are grown at 19°C using sitting-drop vapor-diffusion method, X-ray diffraction structure determination and crystal structure analysis | Bacillus subtilis |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
membrane protein SpoIVFA + H2O | Bacillus subtilis | sequenctial processing by the enzyme together with protease 4B. The 4FA regulatory protein is composed of a globular N-terminal domain, a transmembrane helix (residues 73-90), an unstructured linker region and a compact C-terminal domain (residues 160-255, LytM-like) extending into the intermembrane space. 4B/CtpB-mediated removal of 4FA residues 131-154 induces sK maturation | ? | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Bacillus subtilis | O35002 | - |
- |
Purification (Comment) | Organism |
---|---|
recombinant His-tagged enzyme from Escherichia coli strains BL21(DE3)pLysS or B834(DE3) by nickel affinity chromatography and gel filtration | Bacillus subtilis |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
membrane protein SpoIVFA + H2O | - |
Bacillus subtilis | ? | - |
? | |
membrane protein SpoIVFA + H2O | sequenctial processing by the enzyme together with protease 4B. The 4FA regulatory protein is composed of a globular N-terminal domain, a transmembrane helix (residues 73-90), an unstructured linker region and a compact C-terminal domain (residues 160-255, LytM-like) extending into the intermembrane space. 4B/CtpB-mediated removal of 4FA residues 131-154 induces sK maturation | Bacillus subtilis | ? | - |
? |
Subunits | Comment | Organism |
---|---|---|
dimer | the CtpB protease is organized as a dimeric ring with the catalytic site burried within a tunnel, domain organization of CtpB, overview | Bacillus subtilis |
Synonyms | Comment | Organism |
---|---|---|
CtpB | - |
Bacillus subtilis |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
25 | - |
assay at | Bacillus subtilis |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.5 | - |
assay at | Bacillus subtilis |
General Information | Comment | Organism |
---|---|---|
evolution | the enzyme CtpB belongs to the widespread family of PDZ-proteases | Bacillus subtilis |
additional information | the CtpB protease is organized as a dimeric ring with the catalytic site burried within a tunnel. The PDZ domain controls access to the protease tunnel. Residues Ser309, Lys334, and Gln338 function as catalytic triad mediating cleavage of the 4FA substrate. A peptide ligand, which copurifies and cocrystallizes with CtpB, is observed at the entrance of the protease tunnel near the catalytic triad | Bacillus subtilis |
physiological function | spore formation in Bacillus subtilis relies on a regulated intramembrane proteolysis pathway, involving the enzyme, that synchronizes mother-cell and forespore development. Activating protease CtpB assembles a gated protease tunnel regulating cell-cell signaling during spore formation. Activation of the SpoIV RIP pathway is induced by the concerted activity of enzyme CtpB and a second signaling protease, SpoIVB. Molecular basis of this SpoIV transmembrane signaling, the enzyme resembles a minimal version of a self-compartmentalizing protease regulated by a unique allosteric mechanism, overview | Bacillus subtilis |