ACT_SITE 575; /note="Charge relay system"; /evidence="ECO:0000250"; ACT_SITE 707; /note="Charge relay system"; /evidence="ECO:0000250"; ACT_SITE 783; /note="Charge relay system"; /evidence="ECO:0000250"; ACT_SITE 882; /note="Proton donor"; /evidence="ECO:0000255|PROSITE-ProRule:PRU10003"