Sequence alignment between 4zc3(A) and UniProt seq P68928 (TERS_BPSF6):

P68928 (TERS_BPSF6): Terminase small subunit from Bacillus phage SF6
                 10        20        30        40        50        60        70        80        90       100       110       120       130       140     
         ---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+-----
UniProt: MKEPKLSPKQERFIEEYFINDMNATKAAIAAGYSKNSASAIGAENLQKPAIRARIDARLKEINEKKILQANEVLEHLTRIALGQEKEQVLMGIGKGAETKTHVEVSAKDRIKALELLGKAHAVFTDKQKVETNQVIIVDDSGDAE
PDB seq: -----LSPKQERFIEEYFINDMNATKAAIAAGYSKNSASAIGAENLQKPAIRARIDARLKEI-----------------------------------------------------------------------------------
              ----+---------+---------+---------+---------+---------+--                                                                                   
                 10        20        30        40        50        60