Assuntos
Proteínas de Ligação a DNA/isolamento & purificação , Proteínas de Ligação a DNA/metabolismo , RNA Polimerases Dirigidas por DNA/isolamento & purificação , RNA Polimerases Dirigidas por DNA/metabolismo , Escherichia coli/metabolismo , Podoviridae/enzimologia , Transativadores/metabolismo , Transcrição Gênica , Sequência de Bases , Cromatografia de Afinidade/métodos , Clonagem Molecular , RNA Polimerases Dirigidas por DNA/genética , Escherichia coli/genética , Radioisótopos de Fósforo , Plasmídeos , Podoviridae/genética , Reação em Cadeia da Polimerase , Regiões Promotoras Genéticas , Técnica de Diluição de Radioisótopos , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Moldes Genéticos , Uridina Trifosfato/metabolismo , Vírion/enzimologia , Vírion/genéticaRESUMO
The bifurcated needle technique for BCG vaccination was compared with intradermal injection in a mass BCG and smallpox vaccination programme in Afghanistan. In all population groups the bifurcated needle technique produced substantial tuberculin sensitivity, which however was significantly inferior to that following intradermal injection. The advantages of the bifurcated needle technique did not result in a significant increase in vaccination coverage and output. Under the present circumstances vaccination by bifurcated needle would probably be more expensive than intradermal vaccination.
Assuntos
Vacina BCG/administração & dosagem , Adolescente , Criança , Pré-Escolar , Humanos , Lactente , Injeções Intradérmicas , Agulhas , Teste Tuberculínico , Vacinação/instrumentaçãoRESUMO
Bacteriophage N4 virion RNA polymerase transcription of double-stranded promoter-containing DNAs requires supercoiled template and E. coli single-stranded DNA-binding protein (EcoSSB); other single-stranded DNA-binding proteins cannot substitute. The DNA determinants of virion RNA polymerase binding at the promoter comprise a small template-strand hairpin. The requirement for EcoSSB is surprising, since single-stranded DNA-binding proteins destabilize hairpin structures. DNA footprinting of EcoSSB on wild-type and mutant promoters indicates that EcoSSB stabilizes the template-strand hairpin owing to the hairpin-loop sequences. Other single-stranded DNA-binding proteins destabilize the promoter hairpin, explaining the specificity of EcoSSB activation. We conclude that EcoSSB activates transcription by providing the appropriate DNA structure for polymerase binding. The existence of small hairpins stable to single-stranded protein binding suggests a novel mechanism that provides structural determinants for specific recognition in single-stranded DNA transactions by an otherwise nonspecific DNA-binding protein.
Assuntos
Proteínas de Ligação a DNA/fisiologia , RNA Polimerases Dirigidas por DNA/genética , Escherichia coli/fisiologia , Podoviridae/genética , Sequência de Bases , Pegada de DNA , DNA Bacteriano/química , DNA Bacteriano/metabolismo , DNA de Cadeia Simples/genética , DNA Viral/genética , Desoxirribonuclease I/metabolismo , Escherichia coli/química , Regulação Bacteriana da Expressão Gênica/fisiologia , Regulação Viral da Expressão Gênica/fisiologia , Dados de Sequência Molecular , Conformação de Ácido Nucleico , Regiões Promotoras Genéticas/genética , Sequências Repetitivas de Ácido Nucleico , Transcrição Gênica/genéticaRESUMO
The complete sequence of the polycystic kidney disease gene (PKD1) and its transcript have been described. The predicted protein is not a member of a previously described gene family, but contains several structural motifs that are present in proteins of known function. Most of these domains are present in the extracellular parts of proteins involved in interactions with other proteins and carbohydrates. The PKD1 gene product also contains potential transmembrane sequences. The molecule is likely to be involved in cell-cell or cell-matrix interactions, which is consistent with the different manifestations of polycystic kidney disease.
Assuntos
Genes , Proteínas/genética , Humanos , Rim Policístico Autossômico Dominante/genética , Proteínas/fisiologia , Relação Estrutura-Atividade , Canais de Cátion TRPPRESUMO
The mutated gene responsible for the tubby obesity phenotype has been identified by positional cloning. A single base change within a splice donor site results in the incorrect retention of a single intron in the mature tub mRNA transcript. The consequence of this mutation is the substitution of the carboxy-terminal 44 amino acids with 24 intron-encoded amino acids. The normal transcript appears to be abundantly expressed in the hypothalamus, a region of the brain involved in body weight regulation. Variation in the relative abundance of alternative splice products is observed between inbred mouse strains and appears to correlate with an intron length polymorphism. This allele of tub is a candidate for a previously reported diet-induced obesity quantitative trait locus on mouse chromosome 7.