Fig. 1. m₃G cap formation of TLC1 is dependent on Tgs1. (A) Whole cell extracts were prepared from wild-type and tgs1 cells. After precipitation using an antibody against the m₃G structure, RNA was extracted and analyzed by northern blotting. For hybridization, the random primed [ ³²P]dCTP-labeled TLC1 DNA was used as a probe. Input (10%), anti-m₃G immunoprecipitates (RNA immunoprecipitates of the m₃G antibody; 90%) and supernatant (unbound RNA; 25%) are shown. Duplicates of immunoprecipitates and supernatant were loaded. (B) Telomeres are elongated in the absence of Tgs1. Genomic DNA was prepared from wild-type and tgs1 cells and digested with XhoI. DNA fragments were analyzed by Southern blotting. As a probe, a CA-rich fragment of telomere VII was labeled with [ ³²P]dCTP. Two wild-type and three tgs1 genomic DNA preparations are shown. Black and white arrows indicate the average telomere length in the WT and tgs1 mutant, respectively. (C) Telomeres are elongated in the catalytically inactive tgs1-W178A mutant. Genomic DNA was analyzed as in B. Black and white arrows indicate the average telomere length in the WT and tgs1 mutant, respectively.