Sequence alignment between 1k2d(B) and UniProt seq P06344 (HB2U_MOUSE):

P06344 (HB2U_MOUSE): H-2 class II histocompatibility antigen, A-U beta 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       260   
         ---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---
UniProt: MALQIPSLLLLAAVVVLMVLSSPGTEGGDSERHFVVQFQPFCYFTNGTQRIRYVTRYIYNREEYLRFDSDVGEYRAVTELGRPDAEYYNKQYLERTRAELDTVCRYNYEETEVPTSLRRLEQPNVVISLSRTEALNHHNTLVCSVTDFYPAKIKVRWFRNGQEETVGVSSTQLIRNGDWTFQVLVMLEMTPRRGEVYTCHVEHPSLKSPITVEWRAQSESARSKMLSGIGGCVLGVIFLGLGLFIRHRSQKGPRGPPPAGLLQ
PDB seq: -------------------------------RHFVVQFQPFCYFTNGTQRIRYVTRYIYNREEYLRFDSDVGEYRAVTELGRPDAEYYNKQYLERTRAELDTVCRYNYEETEVPTSLRRLEQPNVVISLSRTEALNHHNTLVCSVTDFYPAKIKVRWFRNGQEETVGVSSTQLIRNGDWTFQVLVMLEMTPRRGEVYTCHVEHPSLKSPITVEWRA-----------------------------------------------
                                        -----+---------+---------+---------+---------+---------+-------+---------+----------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+                                               
                                            10        20        30        40        50        60      70        80         90       100       110       120       130       140       150       160       170       180       190