Chromosomal location and structure of the operon encoding peptide-chain-release factor 2 of Escherichia coli.
The prfB gene encodes peptide-chain-release factor 2 of Escherichia coli, which catalyzes translation termination at UGA and UAA codons. The gene, identified by sequencing, is located at the 62-min region of the E. coli chromosome. The prfB gene is followed by an open reading frame encoding a 57,603-Da protein. This downstream open reading frame was identified as herC, a gene defined by a suppressor mutation that restores replication of a ColE1 plasmid mutant. RNA blot hybridization and S1 nuclease protection analyses of in vivo transcripts showed that prfB and herC are cotranscribed into a 2800-base transcript in the counterclockwise direction with respect to the E. coli genetic map. Thus, we refer to the two genes as the prfB-herC operon. Data are presented that suggest that supK, a mutation in Salmonella typhimurium that suppresses UGA termination, is the structural gene for Salmonella release factor 2. Translation control within the prfB-herC operon and the relationship of these genes to a tRNA methyltransferase are discussed.
Kawakami
K
K
Department of Tumor Biology, University of Tokyo, Japan.
Jönsson
Y H
YH
Björk
G R
GR
Ikeda
H
H
Nakamura
Y
Y
D000595:Amino Acid Sequence; D001483:Base Sequence; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D003062:Codon / Q000235:genetics; D004247:DNA / Q000235:genetics; D004720:Endonucleases; D004926:Escherichia coli / Q000235:genetics*; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D009154:Mutation; D009693:Nucleic Acid Hybridization; D009876:Operon; D010454:Peptide Termination Factors / Q000235:genetics*; D010957:Plasmids; D014176:Protein Biosynthesis; D012313:RNA / Q000235:genetics; D012486:Salmonella typhimurium / Q000235:genetics; D015719:Single-Strand Specific DNA and RNA Endonucleases; D013489:Suppression, Genetic; D014158:Transcription, Genetic
D003062:Codon; D010454:Peptide Termination Factors; C041460:peptide chain termination release factor 2; D012313:RNA; D004247:DNA; D004720:Endonucleases; D015719:Single-Strand Specific DNA and RNA Endonucleases