InterPro domain: IPR044960

This family represents ribulose bisphosphate carboxylase/oxygenase activase (Rubisco activase), which is a metabolic repair enzyme that acts as a molecular chaperone to remodel inhibited active sites of Rubisco, releasing tightly bound sugar phosphates [ 1 ]. This family also includes Protein POST-ILLUMINATION CHLOROPHYLL FLUORESCENCE INCREASE (PIFI, At3g15840), which is involved in NAD(P)H dehydrogenase complex-mediated chlororespiratory electron transport that mediates electron flow from stromal reductants to the plastoquinone (PQ) pool during chlorophyll fluorescence increase after turning off actinic light. Its C-terminal redox-modulated domain is similar to that of the 46-kD isoform of Rubisco activase [ 2 ].

1. Probing the rice Rubisco-Rubisco activase interaction via subunit heterooligomerization. Proc Natl Acad Sci U S A 116, 24041-24048
2. A novel nucleus-encoded chloroplast protein, PIFI, is involved in NAD(P)H dehydrogenase complex-mediated chlororespiratory electron transport in Arabidopsis. Plant Physiol 144, 1742-52