Sequence alignment between 3ofb(U) and UniProt seq P68679 (RS21_ECOLI):

P68679 (RS21_ECOLI): 30S ribosomal protein S21 from Escherichia coli (strain K12) 
                 10        20        30        40        50        60        70 
         ---------+---------+---------+---------+---------+---------+---------+-
UniProt: MPVIKVRENEPFDVALRRFKRSCEKAGVLAEVRRREFYEKPTTERKRAKASAVKRHAKKLARENARRTRLY
PDB seq: ---IKVRENEPFDVALRRFKRSCEKAGVLAEVRRREFYEKPTTERKRAKASAVK-----------------
            -------+---------+---------+---------+---------+---                 
                  10        20        30        40        50