Sequence alignment between 1ieb(A) and UniProt seq P01904 (HA21_MOUSE):

P01904 (HA21_MOUSE): H-2 class II histocompatibility antigen, E-D alpha chain from Mus musculus
                 10        20        30        40        50        60        70        80        90       100       110       120       130       140       150       160       170       180       190       200       210       220       230       240       250     
         ---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+-----
UniProt: MATIGALVLRFFFIAVLMSSQKSWAIKEEHTIIQAEFYLLPDKRGEFMFDFDGDEIFHVDIEKSETIWRLEEFAKFASFEAQGALANIAVDKANLDVMKERSNNTPDANVAPEVTVLSRSPVNLGEPNILICFIDKFSPPVVNVTWLRNGRPVTEGVSETVFLPRDDHLFRKFHYLTFLPSTDDFYDCEVDHWGLEEPLRKTWEFEEKTLLPETKENVMCALGLFVGLVGIVVGIILIMKGIKKRNVVERRQGAL
PDB seq: -------------------------IKEEHTIIQAEFYLLPDKRGEFMFDFDGDEIFHVDIEKSETIWRLEEFAKFASFEAQGALANIAVDKANLDVMKERSNNTPDANVAPEVTVLSRSPVNLGEPNILICFIDKFSPPVVNVTWLRNGRPVTEGVSETVFLPRDDHLFRKFHYLTFLPSTDDFYDCEVDHWGLEEPLRKTWEFEE------------------------------------------------
                                  ---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+--                                                
                                          10        20        30        40        50        60        70        80        90       100       110       120       130       140       150       160       170       180