ATP synthase F0 sector subunit a 247 F-ATPase subunit IV Key component of the proton channel; it plays a direct role in the translocation of protons across the membrane (By similarity). atpI ATPI_ORYSJ ATP synthase subunit a, chloroplastic Nip041 MNIIPCSIKTLKGLYDISGVEVGQHFYWQIGGFQIHAQVLITSWVVITILLGSVIIAVRNPQTIPTDGQNFFEYVLEFIRDLSKTQIGEEYGPWVPFIGTMFLFIFVSNWSGALLPWKIIQLPHGELAAPTNDINTTVALALLTSAAYFYAGLSKKGLSYFEKYIKPTPILLPINILEDFTKPLSLSFRLFGNILADELVVVVLVSLVPLVVPIPVMFLGLFTSGIQALIFATLAAAYIGESMEGHH