Sequence alignment between 3sfd(D) and UniProt seq A5GZW8 (DHSD_PIG):

A5GZW8 (DHSD_PIG): Succinate dehydrogenase [ubiquinone] cytochrome b small subunit, mitochondrial from Sus scrofa
                 10        20        30        40        50        60        70        80        90       100       110       120       130       140       150         
         ---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------
UniProt: MATLWRLSVLCGARGGGALVLRTSVVRPAHVSAFLQDRHTPGWCGVQHIHLSPSHQASSKAASLHWTGERVVSVLLLGLLPAAYLNPCSAMDYSLAAALTLHGHWGIGQVVTDYVRGDALQKVAKAGLLALSAFTFAGLCYFNYHDVGICKAVAMLWKL
         ..........................................................................................................................X....................................
PDB seq: ---------------------------------------------------------SSKAASLHWTGERVVSVLLLGLLPAAYLNPCSAMDYSLAAALTLHGHWGIGQVVTDYVRGDALQKAAKAGLLALSAFTFAGLCYFNYHDVGICKAVAMLWKL
                                                                  -----+---------+---------+---------+---------+---------+---------+---------+---------+---------+------
                                                                      40        50        60        70        80        90       100       110       120       130