>tr|A0A2I8SBI0|A0A2I8SBI0_9ENTR Small ribosomal subunit protein bS21 OS=Citrobacter freundii complex sp. CFNIH3 GN=rpsU MPVIKVRENEPFDVALRRFKRSCEKAGVLAEVRRREFYEKPTTERKRAKASAVKRHAKKL ARENARRTRLY