The default state of the membrane-localized histidine kinase PrrB of rhodobacter sphaeroides 2.4.1 is in the kinase-positive mode

Research demonstrates that central transmembrane domain and a periplasmic loop of the membrane-bound PrrB histidine kinase participate in both sensing and signal transduction in Rhodobacter sphaeroides. The degree of signal transduction is dependent on the ability of the transmembrane domain to sense the inhibitory signal from the terminal oxidase.