title: Yeast tRNA ligase mutants are nonviable and accumulate tRNA splicing intermediates.
abstract: We show here that yeast tRNA ligase protein is essential in the cell and participates in joining together tRNA half-molecules resulting from excision of the intron by the splicing endonuclease. A haploid yeast strain carrying a chromosomal deletion of the ligase gene is viable only if ligase protein can be supplied from a plasmid copy of the gene. When synthesis of the plasmid-borne ligase gene is repressed, cells eventually die and accumulate endonuclease cut but unligated half-molecules and intervening sequences. Half-molecules that accumulate appear to be fully end-processed. Two temperature-sensitive ligase mutant strains have been isolated; these strains accumulate a similar set of unligated half-molecules at the nonpermissive temperature.
authors.affiliation: Department of Biochemistry, University of Rochester School of Medicine and Dentistry, New York 14642.
authors.forename: E M
authors.initials: EM
authors.lastname: Phizicky
authors.forename: S A
authors.initials: SA
authors.lastname: Consaul
authors.forename: K W
authors.initials: KW
authors.lastname: Nehrke
authors.forename: J
authors.initials: J
authors.lastname: Abelson
mesh_terms: D002872:Chromosome Deletion; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D009154:Mutation; D010957:Plasmids; D011130:RNA Ligase (ATP) / Q000235:genetics*; D012326:RNA Splicing; D012343:RNA, Transfer / Q000235:genetics*; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013696:Temperature
chemical_list: D012343:RNA, Transfer; D011130:RNA Ligase (ATP)