The expression and regulation of hsdK genes after conjugative transfer
| Autor: | Jun-ichi Ryu, Ainu Prakash-Cheng, Stephen S. Chung |
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| Rok vydání: | 1993 |
| Předmět: |
Operon
Mutant lac operon Biology medicine.disease_cause F Factor Plasmid Gene expression Genes Regulator Genetics medicine Escherichia coli RNA Messenger Promoter Regions Genetic Molecular Biology Gene Deoxyribonucleases Type I Site-Specific Chromosome Mapping Promoter Gene Expression Regulation Bacterial Chromosomes Bacterial Molecular biology Genes Bacterial Conjugation Genetic |
| Zdroj: | Moleculargeneral genetics : MGG. 241(5-6) |
| ISSN: | 0026-8925 |
| Popis: | The type I restriction and modification genes of Escherichia coli can be transferred to other non-modified strains by conjugation without killing the recipient, implying that the restriction function must be regulated. In this study, two isogenic F′ plasmids (r K + and (r K − served as donors in quantitative conjugation experiments with various restriction-deficient strains of E. coli and Salmonella typhimurium. Conjugation studies with hsd::lacZ operon fusions in F′ plasmids indicate that both of the hsd K promoters, p res, and p mod, express simultaneously following conjugative transfer. Thus these genes do not appear to be regulated at the transcriptional level. A spontaneous mutant of E. coli C was discovered that is presumably killed upon conjugative transfer of the hsd K genes (defined as a Crc− phenotype). The gene that is defective in the mutant was tentatively designated hsdC (control). Hfr gene replacement studies led to the localization of the putative hsdC gene between 6 and 16 min on the E. coli genetic map. |
| Databáze: | OpenAIRE |
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