Viability of Escherichia coli K-12 DNA adenine methylase (dam) mutants requires increased expression of specific genes in the SOS regulon
✍ Scribed by Peterson, Kenneth R. ;Wertman, Kenneth F. ;Mount, David W. ;Marinus, M. G.
- Publisher
- Springer
- Year
- 1985
- Tongue
- English
- Weight
- 774 KB
- Volume
- 201
- Category
- Article
- ISSN
- 0026-8925
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✦ Synopsis
We have examined the level of expression of the SOS regulon in cells lacking DNA adenine methylase activity (darn-). Mud (Ap, lac) fusions to several SOS operons (recA, lexA, uvrA, uvrB, uvrD, sulA, dinD and dinF) were found to express higher levels of fl-galactosidase in darn-strains than in isogenic darn + strains. The attempted construction of darn-strains that were also mutant in one of several SOS genes indicated that the viability of methylase-deficient strains correlates with the inactivation of the SOS repressor (LexA protein). Consistent with this, the wild-type functions of two LexA-repressed genes (recA and ruv) appear to be required for darn-strain viability.