Biomaterial Database

Glutamine is incorporated at the nonsense codons UAG and UAA in a suppressor-free Escherichia coli strain. 2003

Michaela Nilsson, and Monica Rydén-Aulin

Department of Microbiology, Stockholm University, S-106 91, Stockholm, Sweden.

Readthrough of the nonsense codons UAG, UAA, and UGA is seen in Escherichia coli strains lacking tRNA suppressors. Earlier results indicate that UGA is miscoded by tRNA(Trp). It has also been shown that tRNA(Tyr) and tRNA(Gln) are involved in UAG and UAA decoding in several eukaryotic viruses as well as in yeast. Here we have investigated which amino acid(s) is inserted in response to the nonsense codons UAG and UAA in E. coli. To do this, the stop codon in question was introduced into the staphylococcal protein A gene. Protein A binds to IgG, which facilitates purification of the readthrough product. We have shown that the stop codons UAG and UAA direct insertion of glutamine, indicating that tRNA(Gln) can read the two codons. We have also confirmed that tryptophan is inserted in response to UGA, suggesting that it is read by tRNA(Trp).

UI	MeSH Term	Description	Entries
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D005973	Glutamine	A non-essential amino acid present abundantly throughout the body and is involved in many metabolic processes. It is synthesized from GLUTAMIC ACID and AMMONIA. It is the principal carrier of NITROGEN in the body and is an important energy source for many cells.	D-Glutamine,L-Glutamine,D Glutamine,L Glutamine
D012351	RNA, Transfer, Gln	A transfer RNA which is specific for carrying glutamine to sites on the ribosomes in preparation for protein synthesis.	Glutamine-Specific tRNA,Transfer RNA, Gln,tRNAGln,tRNA(Gln),Gln Transfer RNA,Glutamine Specific tRNA,RNA, Gln Transfer,tRNA, Glutamine-Specific
D012364	RNA, Transfer, Trp	A transfer RNA which is specific for carrying tryptophan to sites on the ribosomes in preparation for protein synthesis.	TRNATrp,Transfer RNA, Trp,Tryptophan-Specific tRNA,tRNA(Trp),RNA, Trp Transfer,Trp Transfer RNA,Tryptophan Specific tRNA,tRNA, Tryptophan-Specific
D013489	Suppression, Genetic	Mutation process that restores the wild-type PHENOTYPE in an organism possessing a mutationally altered GENOTYPE. The second "suppressor" mutation may be on a different gene, on the same gene but located at a distance from the site of the primary mutation, or in extrachromosomal genes (EXTRACHROMOSOMAL INHERITANCE).	Suppressor Mutation,Genetic Suppression,Genetic Suppressions,Mutation, Suppressor,Mutations, Suppressor,Suppressions, Genetic,Suppressor Mutations
D014176	Protein Biosynthesis	The biosynthesis of PEPTIDES and PROTEINS on RIBOSOMES, directed by MESSENGER RNA, via TRANSFER RNA that is charged with standard proteinogenic AMINO ACIDS.	Genetic Translation,Peptide Biosynthesis, Ribosomal,Protein Translation,Translation, Genetic,Protein Biosynthesis, Ribosomal,Protein Synthesis, Ribosomal,Ribosomal Peptide Biosynthesis,mRNA Translation,Biosynthesis, Protein,Biosynthesis, Ribosomal Peptide,Biosynthesis, Ribosomal Protein,Genetic Translations,Ribosomal Protein Biosynthesis,Ribosomal Protein Synthesis,Synthesis, Ribosomal Protein,Translation, Protein,Translation, mRNA,mRNA Translations
D017422	Sequence Analysis, DNA	A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.	DNA Sequence Analysis,Sequence Determination, DNA,Analysis, DNA Sequence,DNA Sequence Determination,DNA Sequence Determinations,DNA Sequencing,Determination, DNA Sequence,Determinations, DNA Sequence,Sequence Determinations, DNA,Analyses, DNA Sequence,DNA Sequence Analyses,Sequence Analyses, DNA,Sequencing, DNA
D018389	Codon, Nonsense	An amino acid-specifying codon that has been converted to a stop codon (CODON, TERMINATOR) by mutation. Its occurance is abnormal causing premature termination of protein translation and results in production of truncated and non-functional proteins. A nonsense mutation is one that converts an amino acid-specific codon to a stop codon.	Codon, Termination, Premature,Codon, Unassigned,Mutation, Nonsense,Nonsense Codon,Nonsense Mutation,Premature Stop Codon,Unassigned Codon,Amber Nonsense Codon,Amber Nonsense Mutation,Nonsense Codon, Amber,Ochre Nonsense Codon,Ochre Nonsense Mutation,Opal Nonsense Codon,Opal Nonsense Mutation,Premature Termination Codon,Amber Nonsense Codons,Amber Nonsense Mutations,Codon, Amber Nonsense,Codon, Ochre Nonsense,Codon, Opal Nonsense,Codon, Premature Stop,Codon, Premature Termination,Codons, Amber Nonsense,Codons, Nonsense,Codons, Ochre Nonsense,Codons, Opal Nonsense,Codons, Premature Stop,Codons, Premature Termination,Codons, Unassigned,Mutation, Amber Nonsense,Mutation, Ochre Nonsense,Mutation, Opal Nonsense,Mutations, Amber Nonsense,Mutations, Nonsense,Mutations, Ochre Nonsense,Mutations, Opal Nonsense,Nonsense Codon, Ochre,Nonsense Codon, Opal,Nonsense Codons,Nonsense Codons, Amber,Nonsense Codons, Ochre,Nonsense Codons, Opal,Nonsense Mutation, Amber,Nonsense Mutation, Ochre,Nonsense Mutation, Opal,Nonsense Mutations,Nonsense Mutations, Amber,Nonsense Mutations, Ochre,Nonsense Mutations, Opal,Ochre Nonsense Codons,Ochre Nonsense Mutations,Opal Nonsense Codons,Opal Nonsense Mutations,Premature Stop Codons,Premature Termination Codons,Stop Codon, Premature,Stop Codons, Premature,Termination Codon, Premature,Termination Codons, Premature,Unassigned Codons