Sequence alignment between 4y2d(B) and UniProt seq P01887 (B2MG_MOUSE):

P01887 (B2MG_MOUSE): Beta-2-microglobulin from Mus musculus
                 10        20        30        40        50        60        70        80        90       100       110         
         ---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------
UniProt: MARSVTLVFLVLVSLTGLYAIQKTPQIQVYSRHPPENGKPNILNCYVTQFHPPHIEIQMLKNGKKIPKVEMSDMSFSKDWSFYILAHTEFTPTETDTYACRVKHASMAEPKTVYWDRDM
PDB seq: --------------------IQKTPQIQVYSRHPPENGKPNILNCYVTQFHPPHIEIQMLKNGKKIPKVEMSDMSFSKDWSFYILAHTEFTPTETDTYACRVKHASMAEPKTVYWDR--
                             ---------+---------+---------+---------+---------+---------+---------+---------+---------+-------  
                                     10        20        30        40        50        60        70        80        90