Sequence alignment between 1a90(A) and UniProt seq P01038 (CYT_CHICK):

P01038 (CYT_CHICK): Cystatin from Gallus gallus
                 10        20        30        40        50        60        70        80        90       100       110       120       130         
         ---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------
UniProt: MAGARGCVVLLAAALMLVGAVLGSEDRSRLLGAPVPVDENDEGLQRALQFAMAEYNRASNDKYSSRVVRVISAKRQLVSGIKYILQVEIGRTTCPKSSGDLQSCEFHDEPEMAKYTTCTFVVYSIPWLNQIKLLESKCQ
         ...................................................X...........................................................X...........................
PDB seq: -------------------------------GAPVPVDENDEGLQRALQFAIAEYNRASNDKYSSRVVRVISAKRQLVSGIKYILQVEIGRTTCPKSSGDLQSCEFHDEPELAKYTTCTFVVYSIPWLNQIKLLESKCQ
                                        -+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+------
                                        10        20        30        40        50        60        70        80        90       100       110