Mitochondrial transfer RNAs in yeast: identification of isoaccepting transfer RNAs

Journal Article · Tue May 02 04:00:00 EDT 1978 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00602a008· OSTI ID:7091375

Martin, N C; Rabinowitz, M

To delineate the total number of tRNAs encoded by yeast mitochondrial DNA (mtDNA), we have examined mitochondrial tRNA preparations for the presence of heterogenic isoaccepting tRNAs. Analyses of /sup 3/H-labeled aminoacylated mitochondrial tRNAs by reversed-phase column chromatography (RPC-5) coupled with hybridization to mtDNA detected only one major mitochondrially coded tRNA for alanine, arginine, aspartic acid, glycine, histidine, isoleucine, leucine, lysine, proline, serine, and tryptophan. Some of these profiles also contained one or more minor peaks that may represent small amounts of heterogenic isoacceptors, but their low concentrations prevented their characterization. Cysteinyl-, methionyl-, phenylalanyl-, threonyl-, tyrosyl-, and valyl-tRNAs separated into multiple species upon RPC-5 chromatography. Two cysteinyl-, two methionyl-, two phenylalanyl-, two threonyl-, four tyrosyl-, and two valyl-tRNA species hybridized to mtDNA. The hybridization of the phenylalanyl- and the valyl-tRNA species was not additive, indicating that their sequences are similar, if not identical, and suggesting that they may be transcribed from the same genes. The two methionyl-, and two threonyl-, and probably the two cysteinyl-tRNAs are transcribed from separate genes, since their hybridizations to mtDNA are additive. That the methionyl-tRNAs are transcribed from separate genes was further confirmed through deletion mapping experiments which showed that the genes coding for these tRNAs are at different locations on the mtDNA. The transcriptional relationship of the four tyrosyl-tRNAs was not established. There is at least a cistron coding for tRNAs corresponding to each of the common amion acids except asparagine and several amino acids (methionine, threonine, and cysteine) are accepted by more than one transcriptionally distinct tRNA. Thus, a minimum of 22 tRNA cistrons have been identified.

• Research Organization: Univ. of Chicago
• OSTI ID: 7091375
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 17:9; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550401* -- Genetics-- Tracer Techniques
550701 -- Microbiology-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
BIOMASS
BIOSYNTHESIS
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CHROMATOGRAPHY
DNA
ENERGY SOURCES
FUNGI
GENETIC MAPPING
HYBRIDIZATION
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MICROORGANISMS
MITOCHONDRIA
NUCLEIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANOIDS
PLANTS
PROTEINS
RENEWABLE ENERGY SOURCES
RNA
SEPARATION PROCESSES
SYNTHESIS
TRACER TECHNIQUES
TRANSCRIPTION
TRANSFER RNA
TRITIUM COMPOUNDS
YEASTS