Protein
Pyruvate, phosphate dikinase regulatory protein 1, chloroplastic
Organism
Arabidopsis thaliana
Function
Bifunctional serine/threonine kinase and phosphorylase involved in the dark/light-mediated regulation of PPDK by catalyzing its phosphorylation/dephosphorylation. Dark/light-induced changes in stromal concentrations of the competing ADP and Pi substrates govern the direction of the reaction. In the dark, phosphorylates the catalytic intermediate of PPDK (PPDK-HisP), inactivating it. Light exposure induces the phosphorolysis reaction that reactivates PPDK. Unlike the kinase function which can utilize either Thr or Ser as target, the phosphorylase function has a strict substrate requirement for threonyl phosphate.
Similarity
Belongs to the pyruvate, phosphate/water dikinase regulatory protein family. PDRP subfamily.
Sequence
MALLSAMKLQGRPPPISSNLNPNSKPAGSDSVSLNASEPGSERKPRKFSSQLNRWNRARTLRSGAKLDSTITNGSNNTTGPMRPIESSSRTDVSTLDSDVSSSSNGVSEADMTAAKSIYIVSDGTGWTAEHAVNAALGQFDYCLVDRGCPVNTHLFSGIEDGEKLMEIIKQAAREGAMVIYTLADPSMAEATMRACKLWKIPSLDILGPITESISSHLGTNPSGLSRGITNSSLNEDYFKRIEAIEFTIKHDDGALPENLEKADIVLVGVSRTGKTPLSTYLAQKGYKVSNVPIVNGVDLPKTLFEIDPRKVFGLMINPLVLQGIREARAKSLGLGSSFKTKYSELGSVKEELELAKKIFAENPTWPVIEVTESAIEETAAVVLRLYDERQSNRAMPRISKSY