Kinase Family PAN3
PAN3 is a universal eukaryotic protein involved in RNA de-adenylation, which contains a pseudokinase domain.
NKF1 is found in all or almost all eukaryotes, and has not been reported to ever be duplicated.
The protein contains a pseudokinase domain, followed by a coiled-coil domain and a unique knob domain .
PAN3 binds and regulates PAN2, a deadenylase used for removal of polyA from RNA transcripts, both for general degradation and in response to miRNAs.
Structure and Function of Pseudokinase Domain
The structure of the pseudokinase domain  is highly divergent, though weakly similar to that of Wnk kinases. All three catalytic motifs (VAIK, HRD, DFG) are mutated or absent, as is the activation loop and aspects of the substrate binding and ATP binding regions. However, it does bind ATP, and may use atypical residues to stabilize ATP and Mg . Mutations abolishing ATP binding impair the catalytic activity of the PAN2-PAN3, suggesting that ATP binding may cause a conformational regulatory change in the pseudokinase domain.
- pmid= 23932717