✦ LIBER ✦

Suppression of polarity of insertion mutations within the gal operon of E. coli

✍ Scribed by Besemer, J�rgen ;Herpers, Maria

Publisher: Springer
Year: 1977
Tongue: English
Weight: 959 KB
Volume: 151
Category: Article
ISSN: 0026-8925
DOI: 10.1007/bf00268793

No coin nor oath required. For personal study only.

✦ Synopsis

Phenotypic revertants of galOP::IS1 and galOP::IS2 mutations have been isolated after mutagenesis with nitrosoguanidine, they are probably caused by mutations in gene suA. The polarity suppressor mutations described in this study and a known mutation in gene suA isolated by D. Morse (Morse and Guertin, 1972) suppress polarity caused by IS1 more effectively than that caused by IS2 or IS4. Furthermore, suppressibility is influenced by the site and orientation of IS integration. The synthesis of the three enzymes in galOP::IS suA double mutants is constitutive and the ratio of the three enzymes is altered in comparison to the wild type. The reasons for constitutive synthesis of the galactose enzymes and for the altered ratio of enzyme synthesis are discussed.

📜 SIMILAR VOLUMES

Insertion mutations in the control regio

Insertion mutations in the control region of the Gal operon of E. coli

✍ Saedler, H. ;Besemer, J. ;Kemper, B. ;Rosenwirth, B. ;Starlinger, P. 📂 Article 📅 1972 🏛 Springer 🌐 English ⚖ 464 KB

mRNA distal to polar nonsense and insert

mRNA distal to polar nonsense and insertion mutations in the gal operon of E. coli

✍ Starlinger, P. ;Saedler, H. ;Rak, B. ;Tillmann, E. ;Venkov, P. ;Waltschewa, L. 📂 Article 📅 1973 🏛 Springer 🌐 English ⚖ 508 KB

Insertion mutations in the control regio

Insertion mutations in the control region of the galactose operon of E. coli

✍ Hirsch, H. J. ;Saedler, H. ;Starlinger, P. 📂 Article 📅 1972 🏛 Springer 🌐 English ⚖ 1019 KB

Increased recombinant frequencies with a

Increased recombinant frequencies with an Amber mutation in the Gal-operon of E. coli

✍ Kemper, Börries 📂 Article 📅 1970 🏛 Springer 🌐 English ⚖ 426 KB

Polarity of suppression in the lactose o

Polarity of suppression in the lactose operon

✍ Langridge, J. 📂 Article 📅 1975 🏛 Springer 🌐 English ⚖ 639 KB

The effect of suppression on enzyme synthesis was examined in 43 amber mutations of the gene for beta-galactosidase in Escherichia coli. The ordering of mutations in the gene revealed two clear gradients in the number of molecules of suppressed beta-galactosidase formed by suppression. One gradient

Non-random distribution of deletion endp

Non-random distribution of deletion endpoints in the gal operon of E. coli

✍ Pfeifer, D. ;Hirsch, H. J. ;Bergmann, D. ;Hamlaoui, M. 📂 Article 📅 1974 🏛 Springer 🌐 English ⚖ 662 KB