Sequence alignment between 4b6a(T) and UniProt seq Q02753 (RL21A_YEAST):

Q02753 (RL21A_YEAST): 60S ribosomal protein L21-A from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)
                 10        20        30        40        50        60        70        80        90       100       110       120       130       140       150       160
         ---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+
UniProt: MGKSHGYRSRTRYMFQRDFRKHGAVHLSTYLKVYKVGDIVDIKANGSIQKGMPHKFYQGKTGVVYNVTKSSVGVIINKMVGNRYLEKRLNLRVEHIKHSKCRQEFLERVKANAAKRAEAKAQGVAVQLKRQPAQPRESRIVSTEGNVPQTLAPVPYETFI
PDB seq: -GKSHGYRSRTRYMFQRDFRKHGAVHLSTYLKVYKVGDIVDIKANGSIQKGMPHKFYQGKTGVVYNVTKSSVGVIINKMVGNRYLEKRLNLRVEHIKHSKCRQEFLERVKANAAKRAEAKAQGVAVQLKRQPAQPRESRIVSTEGNVPQTLAPVPYETFI
          --------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+
                 10        20        30        40        50        60        70        80        90       100       110       120       130       140       150       160