Stereoviews of the conserved rRNA core structure in 40S (A) and 60S (B) ribosomal subunits from T. cruzi. The density maps of the 40S and 60S ribosomal subunits are represented in wire mesh. The atomic structures were directly adopted from the rRNA core structure from yeast (Protein Data Bank ID codes 1S1H and 1S1I). Color codes for the conserved rRNA core in the small subunit: domain I, red; domain II, green; domain III, yellow; domain IV, blue. Color codes for the conserved rRNA core in the large subunit: domain I, blue; domain II, cyan; domain III, yellow; domain IV, red; domain V, magenta; domain VI, green; 5S RNA, orange. h, head; bk, beak; tu, turret; h44, helix 44; h33, helix 33; h18, helix 18; h23, helix 23; DC, decoding center; CP, central protuberance; L1, L1 stalk; pr, prong; SB, stalk base; PTC, peptidyl-transferase center; SRL, sarcin–ricin loop; H34, helix 34; H38, helix 38; H68, helix 68; H69, helix 69.