Sequence alignment between 1f1f(A) and UniProt seq P00118 (CYC6_LIMMA):

P00118 (CYC6_LIMMA): Cytochrome c6 from Limnospira maxima
                 10        20        30        40        50        60        70        80         
         ---------+---------+---------+---------+---------+---------+---------+---------+---------
UniProt: GDVAAGASVFSANCAACHMGGRNVIVANKTLSKSDLAKYLKGFDDDAVAAVAYQVTNGKNAMPGFNGRLSPKQIEDVAAYVVDQAEKGW
         .......................................................................X.................
PDB seq: -DVAAGASVFSANCAACHMGGRNVIVANKTLSKSDLAKYLKGFDDDAVAAVAYQVTNGKNAMPGFNGRLSPLQIEDVAAYVVDQAEKGW
          --------+---------+---------+---------+---------+---------+---------+---------+---------
                 10        20        30        40        50        60        70        80