Difference between revisions of "Phosphatase Subfamily PPIP5K"

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[[Phosphatase classification|Phosphatase Classification]]: [[Phosphatase_Fold_HP|Fold HP]]: [[Phosphatase_Superfamily_HP|Superfamily HP]] (histidine phosphatase): [[Phosphatase_Family_HP2|Family HP, branch 2]]: [[Phosphatase_Subfamily_PPIP5K|PPIP5K]]
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[[Phosphatase classification|Phosphatase Classification]]: [[Phosphatase_Fold_HP|Fold HP]]: [[Phosphatase_Superfamily_HP|Superfamily HP]]: [[Phosphatase_Family_HP2|Family HP, branch 2]] (HP2): [[Phosphatase_Subfamily_PPIP5K|Subfamily PPIP5K]]
  
PPIP5K is a phosphoinositol kinase that also has a pseudophosphatase domain which bind to PtdIns(3,4,5)P3. PPIP5K converts InsP6 and 5-InsP7 to 1-InsP7 and InsP8.
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PPIP5K is a phosphoinositol kinase that also has a pseudophosphatase domain which binds to PtdIns(3,4,5)P3. PPIP5K converts InsP6 and 5-InsP7 to 1-InsP7 and InsP8.
  
 
=== Evolution ===
 
=== Evolution ===
PPIP5K is found in most eukaryotes except for some excavate. Most vertebrates have at least two copies, while invertebrates usually have one.
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PPIP5K is found in most eukaryotes, but is missing in alveolates. Most vertebrates have at least two copies, while invertebrates usually have one.
  
 
=== Domain ===
 
=== Domain ===
PPIP5K has two domains: N-terminal RimK/ATP-grasp domain, and C-terminal HP2 domain <cite>fridy07</cite>.  The RimK is the active kinase domain <cite>fridy07, choi07</cite>.
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PPIP5K has two domains: N-terminal RimK/ATP-grasp kinase domain, and C-terminal HP2 phosphatase domain <cite>fridy07</cite>.  The RimK is the active kinase domain <cite>fridy07, choi07</cite>.
  
Unlike other members of HP2 family which are protein or non-protein phosphatases, the HP2 domain of PPIP5K is not catalytically active. Instead, this HP2 domain is specialized for binding PtdIns(3,4,5)P3, as a partial PH (pleckstrin homology) consensus sequence is spliced into this HP2 domain <cite>gokhale11</cite>.
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Unlike other HP2 subfamilies which are protein or non-protein phosphatases, the HP2 domain of PPIP5K is not catalytically active. Instead, it binds PtdIns(3,4,5)P3, in part using an inserted partial PH (pleckstrin homology) domain <cite>gokhale11</cite>. The HP2 domains of PPIP5Ks are longer than those of other HP2 subfamilies, due to insertions at multiple sites.
  
 
=== Catalytic activity and functions ===
 
=== Catalytic activity and functions ===
The phosphatase domains of human PPIP5K1 and PPIP5K2 are catalytically inactive, though they bear the histidine residue at catalytic core (figure 5 in <cite>rigden08</cite>). It is unclear whether PPIP5K are conservatively inactive in other genomes.
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The phosphatase domains of human PPIP5K1 and PPIP5K2 are catalytically inactive, though they bear the histidine residue at catalytic core (figure 5 in <cite>rigden08</cite>). It is unclear whether PPIP5K are inactive in other genomes.
  
 
=== References ===
 
=== References ===

Latest revision as of 18:04, 12 April 2017


Phosphatase Classification: Fold HP: Superfamily HP: Family HP, branch 2 (HP2): Subfamily PPIP5K

PPIP5K is a phosphoinositol kinase that also has a pseudophosphatase domain which binds to PtdIns(3,4,5)P3. PPIP5K converts InsP6 and 5-InsP7 to 1-InsP7 and InsP8.

Evolution

PPIP5K is found in most eukaryotes, but is missing in alveolates. Most vertebrates have at least two copies, while invertebrates usually have one.

Domain

PPIP5K has two domains: N-terminal RimK/ATP-grasp kinase domain, and C-terminal HP2 phosphatase domain [1]. The RimK is the active kinase domain [1, 2].

Unlike other HP2 subfamilies which are protein or non-protein phosphatases, the HP2 domain of PPIP5K is not catalytically active. Instead, it binds PtdIns(3,4,5)P3, in part using an inserted partial PH (pleckstrin homology) domain [3]. The HP2 domains of PPIP5Ks are longer than those of other HP2 subfamilies, due to insertions at multiple sites.

Catalytic activity and functions

The phosphatase domains of human PPIP5K1 and PPIP5K2 are catalytically inactive, though they bear the histidine residue at catalytic core (figure 5 in [4]). It is unclear whether PPIP5K are inactive in other genomes.

References

Error fetching PMID 17690096:
Error fetching PMID 17702752:
Error fetching PMID 21222653:
Error fetching PMID 18092946:
  1. Error fetching PMID 17690096: [fridy07]
  2. Error fetching PMID 17702752: [choi07]
  3. Error fetching PMID 21222653: [gokhale11]
  4. Error fetching PMID 18092946: [rigden08]
All Medline abstracts: PubMed | HubMed