rplU 102 This protein binds to 23S rRNA in the presence of protein L20 (By similarity). RL21_STAAU 50S ribosomal protein L21 MFAIIETGGKQIKVEEGQEIFVEKLDVNEGDTFTFDKVLFVGGDSVKVGAPTVEGATVTATVNKQGRGKKITVFTYKRRKNSXRKKGHRQPYTKLTIDKINA