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Open AccessJournal ArticleDOI

UGA Nonsense Mutations in Salmonella typhimurium

John R. Roth
- 01 May 1970 - 
- Vol. 102, Iss: 2, pp 467-475
TLDR
A selection method is described which permits the isolation of rare UGA mutants isolated from Salmonella typhimurium strain LT-2, and the properties of a prototrophic his UGA mutant are described.
Abstract
Salmonella typhimurium strain LT-2 carries a weak UGA suppressor activity. This activity prevents the detection of some UGA mutants as auxotrophs and probably accounts for the rarity of his UGA mutants in this strain. A selection method is described which permits the isolation of these rare his UGA mutants. Map distribution of his UGA mutations is normal, and their polarity effects are indistinguishable from the polarity effects of amber and ochre mutations at similar locations. Isolation and properties of a prototrophic his UGA mutant are described. UGA mutants are common among lac mutants isolated from Salmonella strains carrying an F'lac episome. Apparently the suppressor activity is insufficient to prevent detection of lac UGA mutants. It is not yet clear whether the suppressor activity plays an important role in normal cell physiology.

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Citations
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Journal ArticleDOI

The 3′-Terminal Sequence of Escherichia coli 16S Ribosomal RNA: Complementarity to Nonsense Triplets and Ribosome Binding Sites

TL;DR: It is suggested that this region of the RNA is able to interact with mRNA and that the 3'-terminal U-U-A(OH) is involved in the termination of protein synthesis through base-pairing with terminator codons.
Journal ArticleDOI

A different genetic code in human mitochondria

TL;DR: Comparison of the human mitochrondrial DNA sequence of the cytochrome oxidase subunit II gene and the sequence of a corresponding beef heart protein shows that UGA is used as a tryptophan codon and not as a termination codon, and suggests that AU A may be a methionine and not an isoleucine codon.
Journal ArticleDOI

Role of the conserved AAUAAA sequence: four AAUAAA point mutants prevent messenger RNA 3' end formation.

TL;DR: ARTICLES The 1984 Nobel Prize in Medicine: J. W. Winkleman, D. L. Taube, and P. Stephenson.
Journal ArticleDOI

Errors and alternatives in reading the universal genetic code.

J Parker
TL;DR: Discussion sur les erreurs faux-sens, les mecanismes de terminaison and de decalages de lecture and les moyens dont dispose la cellule pour controler and s'accommoder de ces erreur.
Journal ArticleDOI

Tryptophan transfer RNA as the UGA suppressor.

TL;DR: It is concluded that UGA suppression is carried out by a tRNATrp whose anticodon-codon recognition is altered by a change elsewhere in the molecule.
References
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Journal ArticleDOI

Acetylornithinase of Escherichia coli: partial purification and some properties.

TL;DR: Compounds Used-N”l-Acetyl-n-ornithine was synthesized as previously described and L-Ornithine monohydrochloride was obtained from the Mann Research Laboratories.
Journal ArticleDOI

The genetic control and cytoplasmic expression of “Inducibility” in the synthesis of β-galactosidase by E. coli

TL;DR: The study of galactosidase synthesis in heteromerozygotes of E. coli indicates that the z and i mutations belong to different cistrons, and the kinetics of expression of the i + (inducible) character suggest that the i gene controls the synthesis of a specific substance which represses the synthesis.
Journal ArticleDOI

A proposal for a uniform nomenclature in bacterial genetics

TL;DR: This proposal was published in Genetics, (1966), 54, 61, but in view of its importance it is reprinted here by permission of the authors and of the Editor and Proprietors of Genetics.
Journal ArticleDOI

Release factors differing in specificity for terminator codons.

TL;DR: In a previous paper, initiator and terminator trinucleotides were shown to stimulate sequentially the binding of f-Met-tRNA to ribosomes and the release of free f-methionine from the ribosomal intermediate.
Journal ArticleDOI

Procedure for identifying nonsense mutations

TL;DR: A method has been devised for the rapid identification of nonsense mutations (UAG, UAA, UGA codons) in Salmonella by replica-printed onto lactose plates spread with lawns of tester strains containing nonsense mutations in the episomal Z gene.
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