An amber mutation in the gene encoding the beta' subunit of Escherichia coli RNA polymerase

1982 ◽  
Vol 152 (2) ◽  
pp. 736-746
Author(s):  
S P Ridley ◽  
M P Oeschger
Keyword(s):  
Escherichia Coli ◽  
High Temperature ◽  
Rna Polymerase ◽  
Coli Strain ◽  
Beta Subunit ◽  
Temperature Sensitive ◽  
Amber Mutation ◽  
Gene Encoding ◽  
Amber Suppressor

An Escherichia coli strain carrying an amber mutation (UAG) in rpoC, the gene encoding the beta prime subunit of RNA polymerase, was isolated after mutagenesis with nitrosoguanidine. The mutation was moved into an unmutagenized strain carrying the supD43,74 allele, which encodes a temperature-sensitive su1 amber suppressor, and sue alleles, which enhance the efficiency of the suppressor. In this background, beta prime is not synthesized at high temperature. Suppression of the mutation by the non-temperature-sensitive amber suppressor su1+ yields a protein which is functional at all temperatures examined (30, 37, and 42 degrees C).

scholarly journals In vitro incorporation of nonnatural amino acids into protein using tRNACys-derived opal, ochre, and amber suppressor tRNAs

RNA ◽  
2010 ◽  
Vol 16 (8) ◽  
pp. 1660-1672 ◽  
Author(s):  
J. Gubbens ◽  
S. J. Kim ◽  
Z. Yang ◽  
A. E. Johnson ◽  
W. R. Skach
Keyword(s):  
Amino Acids ◽  
Nonnatural Amino Acids ◽  
Amber Suppressor

Mapping of the supP (Su6+) Amber Suppressor Gene in Escherichia coli

1980 ◽  
Vol 141 (2) ◽  
pp. 977-978 ◽  
Author(s):  
Ástrós Arnardóttir ◽  
Sigrídur Thorbjarnardóttir ◽  
Gudmundur Eggertsson
Keyword(s):  
Escherichia Coli ◽  
Suppressor Gene ◽  
Amber Suppressor

scholarly journals Novel amber suppressor tRNAs of mammalian origin.

1987 ◽  
Vol 6 (10) ◽  
pp. 3049-3055 ◽  
Author(s):  
R. P. Valle ◽  
M. D. Morch ◽  
A. L. Haenni
Keyword(s):  
Amber Suppressor ◽  
Mammalian Origin

scholarly journals Tetracycline-Regulated Suppression of Amber Codons in Mammalian Cells

1998 ◽  
Vol 18 (8) ◽  
pp. 4418-4425 ◽  
Author(s):  
Ho-Jin Park ◽  
Uttam L. RajBhandary
Keyword(s):  
Mammalian Cells ◽  
Trna Synthetase ◽  
Nonsense Mutations ◽  
Suppressor Trna ◽  
E Coli ◽  
Tetracycline Transactivator ◽  
Hela Cell Lines ◽  
Amber Codon ◽  
Amber Suppressor ◽  
Chloramphenicol Acetyltransferase Gene

ABSTRACT As an approach to inducible suppression of nonsense mutations in mammalian cells, we described recently an amber suppression system in mammalian cells dependent on coexpression of Escherichia coli glutaminyl-tRNA synthetase (GlnRS) along with the E. coli glutamine-inserting amber suppressor tRNA. Here, we report on tetracycline-regulated expression of the E. coli GlnRS gene and, thereby, tetracycline-regulated suppression of amber codons in mammalian HeLa and COS-1 cells. The E. coli GlnRS coding sequence attached to a minimal mammalian cell promoter was placed downstream of seven tandem tetracycline operator sequences. Cotransfection of HeLa cell lines expressing a tetracycline transactivator protein, carrying a tetracycline repressor domain linked to part of a herpesvirus VP16 activation domain, with the E. coli GlnRS gene and the E. coli glutamine-inserting amber suppressor tRNA gene resulted in suppression of the amber codon in a reporter chloramphenicol acetyltransferase gene. The tetracycline transactivator-mediated expression of E. coli GlnRS was essentially completely blocked in HeLa or COS-1 cells grown in the presence of tetracycline. Concomitantly, both aminoacylation of the suppressor tRNA and suppression of the amber codon were reduced significantly in the presence of tetracycline.

scholarly journals Global Transcriptional Effects of a Suppressor tRNA and the Inactivation of the Regulator frmR

2004 ◽  
Vol 186 (20) ◽  
pp. 6714-6720 ◽  
Author(s):  
Christopher D. Herring ◽  
Frederick R. Blattner
Keyword(s):  
Minimal Medium ◽  
Stop Codon ◽  
Open Reading Frames ◽  
Oligonucleotide Microarrays ◽  
Wild Type ◽  
Suppressor Trna ◽  
Cellular Physiology ◽  
Putative Operon ◽  
Amber Suppressor ◽  
Reading Frames

ABSTRACT Expression of an amber suppressor tRNA should result in read-through of the 326 open reading frames (ORFs) that terminate with amber stop codons in the Escherichia coli genome, including six pseudogenes. Abnormal extension of an ORF might alter the activities of the protein and have effects on cellular physiology, while suppression of a pseudogene could lead to a gain of function. We used oligonucleotide microarrays to determine if any effects were apparent at the level of transcription in glucose minimal medium. Surprisingly, only eight genes had significantly different expression in the presence of the suppressor. Among these were the genes yaiN, adhC, and yaiM, forming a single putative operon whose likely function is the degradation of formaldehyde. Expression of wild-type yaiN was shown to result in repression of the operon, while a suppression-mimicking allele lacking the amber stop codon and extended 7 amino acids did not. The operon was shown to be induced by formaldehyde, and the genes have been renamed frmR, frmA, and frmB, respectively.

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