Sequence alignment between 1xer(A) and UniProt seq P55907 (FER1_SULTO):

P55907 (FER1_SULTO): Zinc-containing ferredoxin-1 from Sulfurisphaera tokodaii (strain DSM 16993 / JCM 10545 / NBRC 100140 / 7)
                 10        20        30        40        50        60        70        80        90       100    
         ---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+----
UniProt: MGIDPNYRTNRQVVGEHSGHKVYGPVEPPKVLGIHGTIVGVDFDLCIADGSCINACPVNVFQWYDTPGHPASEKKADPVNEQACIFCMACVNVCPVAAIDVKPP
         .............................X..........................................................................
PDB seq: -GIDPNYRTNRQVVGEHSGHKVYGPVEPPXVLGIHGTIVGVDFDLCIADGSCINACPVNVFQWYDTPGHPASEKKADPVNEQACIFCMACVNVCPVAAIDVKPP
          ---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---
                  10        20        30        40        50        60        70        80        90       100