ACT_SITE 191; /note="Charge relay system"; /evidence="ECO:0000250|UniProtKB:Q99685"; ACT_SITE 256; /note="Charge relay system"; /evidence="ECO:0000250|UniProtKB:O75608"; ACT_SITE 285; /note="Charge relay system"; /evidence="ECO:0000250|UniProtKB:O75608"