PMID:5330222: Difference between revisions
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Table edited by Azweifel via TableEdit |
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*Suppressors of nonsense codons exist for the regulatory ''i'' gene of the lactose operon, thereby proving that the functional i product is a protein. | *Suppressors of nonsense codons exist for the regulatory ''i'' gene of the lactose operon, thereby proving that the functional i product is a protein. | ||
**Rationale: suppression of nonsense codons into amino acids occurs at the translational level | **Rationale: suppression of nonsense codons into amino acids occurs at the translational level | ||
*Specific activity of β-galactosidase in the wild type is 12; in both the suppressible (but unsuppressed) constitutives 18,000. | |||
**values in a large number of different ''su+'' revertants from these two constitutive strains range from 600 to 2000, indicating incomplete suppression and the existence of different suppressors. | |||
== Materials and Methods Used == | == Materials and Methods Used == | ||
Revision as of 21:27, 8 December 2010
| Citation |
Müller-Hill, B (1966) Suppressible regulator constitutive mutants of the lactose system in Escherichia coli.J. Mol. Biol. 15:374-6 |
|---|---|
| Abstract |
No abstract in PubMed |
| Links | |
| Keywords |
Enzyme Repression; Escherichia coli; Galactosidases; Genetic Code; Guanidines; Lactose; Molecular Biology; Mutation; Purines; RNA, Messenger |
| edit table |
Main Points of the Paper
- Suppressors of nonsense codons exist for the regulatory i gene of the lactose operon, thereby proving that the functional i product is a protein.
- Rationale: suppression of nonsense codons into amino acids occurs at the translational level
- Specific activity of β-galactosidase in the wild type is 12; in both the suppressible (but unsuppressed) constitutives 18,000.
- values in a large number of different su+ revertants from these two constitutive strains range from 600 to 2000, indicating incomplete suppression and the existence of different suppressors.
Materials and Methods Used
Please list the materials and methods used in this paper (strains, plasmids, antibodies, etc).
- Mutagenesis of E.coli strain 112-12 (gal-, cys-, his-, su)
- Mutagen-producing agents: 2-aminopurine or N-methyl-N'-nitro-N-nitrosguanidine
- ONPG solution to select for lac constitutive mutants
Phenotype Annotations
| Species | Taxon ID | Strain | Gene (if known) | OMP | Phenotype | Details | Evidence | Notes |
|---|---|---|---|---|---|---|---|---|
|
Escherichia coli |
NCBI:562 |
112-12lacc (gal-cys-his-su-) |
lacI |
decreased beta-galactosidase activity |
Metabolic Activity |
decreased beta-galactosidase activity in the su+ revertants compared to the su- parent |
Biochemical Assay |
LacZ assay |
| edit table |
