Sequence alignment between 4z50(A) and UniProt seq Q0PQ60 (Q0PQ60_9HIV1):

Q0PQ60 (Q0PQ60_9HIV1): Protease (Fragment) from Human immunodeficiency virus 1
                 10        20        30        40        50        60        70        80        90         
         ---------+---------+---------+---------+---------+---------+---------+---------+---------+---------
UniProt: PQITLWQRPFVTVKVGGQLKEALLDTGADNTVFEDIELPGRWKPKMIGGIGGFVKVRQYDQVPIEICGHKAIGTVLVGPTPVNVIGRDFMTQLGCTLNF
         ......X.................X......X....X.........X......X...X........X...X.................X...X.X....
PDB seq: PQITLWKRPFVTVKVGGQLKEALLNTGADNTIFEDINLPGRWKPKMVGGIGGFLKVREYDQVPIEIAGHKVIGTVLVGPTPVNVIGRDTMTQIGATLNF
         ---------+---------+---------+---------+---------+---------+---------+---------+---------+---------
                 10        20        30        40        50        60        70        80        90