FIGURE 3.

Complementation by hClp1 of kinase-ts mutations in yeast and plant tRNA ligases. Functional complementation was tested by spotting on SD-His⁻ agar plates serial 10-fold dilutions of trl1Δ pTRL1-(S444P-I487A) (TRP1 CEN) yeast cells (A) or trl1Δ AtRNL1-R804A (TRP1 CEN) yeast cells (B) that had been transformed with a CEN HIS3 TRL1-(389-827) plasmid or a CEN HIS3 AtRNL-T1001A plasmid (positive controls) or with 2μ HIS3 plasmids bearing genes encoding either wild-type yCLP1, wild-type hCLP1, or hCLP1 kinase active site mutants K127A-S128A or D151A. Cells transformed with the empty 2μ HIS3 vector served as a negative control. The plates were photographed after incubation for 3 d at 25°C, 30°C, 34°C, or 37°C.