RESUMEN
An important component of nonspecific defence of human or animal organisms against microbial invasion is attempt to withhold growth-essential iron from invading bacteria. To overcome the barrier bacterial iron uptake systems is derepressed at low iron concentrations. In many pathogenic and nonpathogenic bacteria the regulation of the corresponding genes depends on the regulatory protein Fur. For cloning Fur-regulated loci, methods based on affinity of Fur to the corresponding promoter sites are used.
Asunto(s)
Bacterias/patogenicidad , Proteínas Bacterianas/genética , Regulación Bacteriana de la Expresión Génica , Genes Bacterianos , Proteínas Represoras/genética , Animales , Bacterias/metabolismo , Infecciones Bacterianas/metabolismo , Proteínas Bacterianas/metabolismo , Genes Reguladores , Técnicas Genéticas , Humanos , Hierro/metabolismo , Proteínas Represoras/metabolismo , Virulencia/genéticaRESUMEN
Data are obtained suggesting the involvement of the cor gene of the [symbol: see text] 80 phage in regulation of phage operons. Mutations in the cor gene, which is located outside the region of phage [symbol: see text] 80 immunity, cause disturbances in the establishment and maintenance of the phage lysogenic state. The cor gene was shown to affect RecA-inactivation of the phage repressor induced by UV-irradiation. A model suggesting cor gene involvement in [symbol: see text] 80 operon regulation is discussed.
Asunto(s)
Bacteriófago lambda/genética , Genes Virales , Lisogenia , Operón , Proteínas Represoras/genética , Bacteriófago lambda/clasificación , Mutación , Rayos UltravioletaRESUMEN
The recombinant plasmid DNA YEp secl-v-sis was constructed. This plasmid was able to code for the synthesis and secretion into the cultural medium of the protein-product of oncogene v-sis. Transcription, copy number and stability of the plasmid DNA were studied under the conditions of galactose induction. The v-sis protein was determined by gel electrophoresis and immunoblotting methods and assayed for cell-proliferation activity in the mammalian cell culture.
Asunto(s)
Oncogenes , Proteínas Oncogénicas de Retroviridae/biosíntesis , Saccharomyces cerevisiae/genética , Factores de Crecimiento Transformadores/biosíntesis , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Proteínas Oncogénicas v-sis , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Mapeo Restrictivo , Proteínas Oncogénicas de Retroviridae/genética , Proteínas Oncogénicas de Retroviridae/metabolismo , Factores de Crecimiento Transformadores/genética , Factores de Crecimiento Transformadores/metabolismoRESUMEN
Mapping of the sites of cleavage of five restriction endonucleases (BglI, BglII, EcoRV, KpnI and PvuII) in the immunity region of bacteriophage phi 80 DNA is described. The order of the 27 restriction sites was established. This helped to localize the phi 80 cI gene within the 640 bp fragment of the immunity region. Recombinant plasmids carrying phi 80 "kil" function were constructed. The function is suppressed by the cI-coded repressor. The deletion AB43 which is present in the phi 80 vir mutant is located within the phi 80 DNA fragment carrying the cI gene.