Nucleic Acids Research, 1981, Vol. 9, No. 4 1019-1029
© 1981
MOLECULAR BIOLOGY |
tRNA synthesis: identification of in vivo precursor tRNAs from parental and mutant yeast strains
1Department of Biological Chemistry, The Milton S. Hershey Medical Center, The Pennsylvania State University Hershey, PA 17033 2Institute of Molecular Biology, University of Oregon Eugene, OR 97403, USA
3To whom correspondence should be addressed
Received October 24, 1980.
In vivo yeast precursor tRNAs have been identified using a modification of the Northern-hybridization procedure. Two species of pre-
and 2 species of pre-tRNA
and 2 species of pre-tRNAminorSer have been found in all yeast strains examined, including parental strains and strains harboring mutations affecting tRNA function. One of the tRNA 1yr precursors and one of the pre-tRNA
are the same size as the unspliced pre-tRNAs which accumulate in the yeast mutant rnal. The in vivo tRNA1yr precursors detected in these studies also appear similar with the RNA species identified when cloned yeast tRNA1yr is transcribed and processed by Xenopus oocytes and/or Xenopus extracts. We have also studied the precursor and mature tRNA1yr species from 22 mutants which contain mutations in the SUP4 tyrosine-inserting suppressor locus. The RNA from 2 mutants mapping at the G52 position showed an aberrantly migrating "mature" tRNA1yr. Although several of those cloned mutant genes showed transcript products of altered size in in vitro transcription studies (1), we did not detect such altered transcripts in vivo.