Sequence alignment between 3a0b(F) and UniProt seq P12239 (PSBF_THEVL):

P12239 (PSBF_THEVL): Cytochrome b559 subunit beta from Thermostichus vulcanus 
                 10        20        30        40     
         ---------+---------+---------+---------+-----
UniProt: MTSNTPNQEPVSYPIFTVRWVAVHTLAVPTIFFLGAIAAMQFIQR
PDB seq: ----------VSYPIFTVRWVAVHTLAVPTIFFLGAIAAMQFIQR
                   ---------+---------+---------+-----
                           20        30        40