Phosphatases are classified by protein structural fold of the catalytic domain, and sub-classified by families and subfamilies based on the sequence of the phosphatase domains as well as by sequences outside of the catalytic domain, and known biochemical and biological functions.
Classification Chart of Protein Phosphatases
|Fold||Superfamily||Family||Substrate||Present in human|
|DSP||pTyr, pSer/pThr, small molecule||Yes|
|AP||AP||AP||pTyr, perhaps pSer/pThr||Yes|
|HP2||pTyr, small molecules||Yes|
|RTR1||RTR1||RTR1||pSer of CTD repeats||Yes|
Synonymns: CC3 = Rhodanese; PPM = PP2C.
Abbreviations: CC1, Cysteine-based Class I; CC2, Cysteine-based Class II; CC3, Cysteine-based Class III; PPPL: PPP-like; PAP, Purple Acid Phosphatase; AP, Alkaline Phosphatase; HP, Histidine Phosphatase; HP1, Histidine Phosphatase, branch 1; HP2, Histidine Phosphatase, branch 2; CTD, RNA Poly II C-Terminal Domain.
Notes of classification
Both FCPs of HAD fold and SSU72 of CC2 fold can dephosphorylate CTD.
Notes on the PTPLA/PTP-like family that was claimed to be a phosphatase, but probably is not.
Some phosphatases only dephosphorylate non-protein substrates, as far as known.
- What are the single-gene subfamilies in nine genomes. We keep them because they are found in at least two genera, although they are not found in the other genome among the nine genomes: dicty, budding yeast, monosiga, sponge, nematostella, C. elegans, Drosophila, sea urchin, and human.