Fig. 4.

The fractionation of cell extracts from WT, ssb1/2Δ, zuo1Δ, and ssz1Δ with and without [PSI+]. Total cell extracts (T) from each strain were separated into a postribosomal supernatant (S) and a ribosomal pellet (P) using ultracentrifugation. Corresponding amounts of T, S, and P fraction were separated by SDS/PAGE, one gel for [psi−] strain extracts and one for [PSI+] extracts, and further analyzed by Western blot, with the use of antibodies specific to Rpl15a, Ssb1/2p, Zuo1p, and Ssz1p, respectively. For better detection of Zuo1p from pellet fractions, both S and P fractions were overloaded by two-fold compared to the T fraction.