The polyribosome profiles of the wild-type parent and deletion mutant cells. Polyribosome preparation was performed by using wild-type BY4741 (A), Δnsr1 (B), Δrpl20a (C), Δbud21 (D), Δrai1 (E), and Δrsm22 (F) cells, grown under normoxic and hypoxic conditions, respectively. Then polyribosome profiles were analyzed by using 7–50% sucrose gradients.