PPM-type phosphatase domain superfamily (IPR036457)
Short name: PPM-type_dom_sf
Protein phosphatases remove phosphate groups from various proteins that are the key components of a number of signalling pathways in eukaryotes and prokaryotes. Protein phosphatases that dephosphorylate Ser and Thr residues are classified into the phosphoprotein (PPP) and the protein phosphatase Mg(2+)- or Mn(2+)-dependent (PPM) families. The core structure of PPMs is the 300-residue PPM-type phosphatase domain that catalyzes the dephosphorylation of phosphoserine- and phosphothreonine-containing protein. The PPM-type phosphatase domain is found as a module in diverse structural contexts and is modulated by targeting and regulatory subunits [PMID: 9003755, PMID: 9869399, PMID: 22115775, PMID: 22668558].
Some proteins known to contain a PPM-type phosphatase domain are listed below:
- Bacillus subtilis stage II sporulation protein E (SpoIIE), controls the sporulation by dephosphorylating an anti-transcription factor SpoIIAA, reversing the actions of the SpoIIAB protein kinase in a process that is gouverned by the ADP/ATP ratio [levdikov].
- Mycobacterium tuberculosis PP2C-family Ser/Thr phosphatase (PstP).
- Eucaryotic PP2C, a negative regulator of protein kinase cascades that are activated as a result of stress.
- Yeast adenyl cyclase, plays essential roles in regulation of cellular metabolism by catalyzing the synthesis of a second messenger, cAMP.
- Mammalian mitochondrial pyruvate dehydrogenase phosphatase 1 (PDP1).
- Plant kinase-associated protein phosphatase (KAPP), regulates receptor-like kinase (RLK) signalling pathways.
- Plant absissic acid-insenstive 1 and 2 (ABI1 and ABI2), play a key absissic acid (ABA) signal transduction.
The PP2C-type phosphatase domain consists of 10 segments of beta-strands and 5 segments of alpha-helix and comprises a pair of detached subdomains. The first is a small beta-sandwich with strand beta1 packed against strands beta2 and beta3; the second is a larger beta-sandwich in which a four-stranded beta- heet packs against a three-stranded beta-sheet with flanking alpha-helices [PMID: 9003755, PMID: 22115775].
This entry represents a conserved region found in the N-terminal part that contains a perfectly conserved tripeptide.