Sensor kinase that senses the plastoquinone (PQ) redox state involved in stoichiometry adjustment of both photosystems (e.g. long-term adaptation via transcriptional regulation of reaction center genes of photosystems I and II) and state transitions (e.g. short-term adaptation involving reversible post-translational phosphorylation of light-harvesting complex II, LHC II), thus linking photosynthesis with gene expression in chloroplasts (By similarity). Reduced PQ suppresses its autophosphorylation activity (Probable). ATP + protein L-histidine = ADP + protein N-phospho-L-histidine. The 3Fe-4S cluster is redox-responsive, probably binds 1 cluster per monomer. Oligomerizes. In this organism the plastid is the result of a secondary endosymbiosis event, and is found within the endomembrane system, necessitating a complex targeting process. Autophosphorylates, possibly on His-292. Probably has a bipartite transit peptide. The signal to cross the ER endomembrane system is probably residues 1-31 while the transit peptide is probably residues 32-50. Belongs to the chloroplast sensor kinase protein family. Extended N-terminus.