Fig. 6: Critical residues of the PLs, the D1-D2 linker and the ISS motifs are important for the in vivo function of Drg1.

a Drg1 pore-loop mutants suppress cell growth. Yeast BY4741 cells carrying different Drg1 variants (E346A/E617A, Y319A, Δ357-361, Δ362-365, Y590A, Δ628-632) were grown to mid-log phase in liquid medium, diluted, and spotted on SC-Ura medium with 2% glucose or galactose and incubated at 30 °C. b Drg1 loop mutants impairs ribosome assembly and lead to a “halfmer” phenotype. Yeast BY4741 cells expressing different variants were lyzed and the lysates were subjected to a sucrose gradient-based polysome profiles analysis. The position of 40S, 60S, 80S, and polysome peaks are indicated. Halfmer peaks on the right shoulders of the 80S and polysome peaks are indicated by arrows. c The mutations on the ISS motif of the D2, and on the D1-D2 linker lead to a slow-growth phenotype. Yeast BY4741 cells carrying different Drg1 variants (R499A M503A, R504A, F507A, E240A, Y236A, P241A, V647R, and M377R) were grown to mid-log phase in liquid medium, diluted, and spotted on SC-Ura medium with 2% glucose or galactose and incubated at 30 °C. d Sucrose gradient polysome profile analysis of yeast cells expressing different Drg1 variants (M503A, R504A, V647R).