RESUMEN
A recombinant DNA library was constructed from partial BamHI or MboI digests of safflower (Carthamus tinctorius L.) chloroplast DNA, in the BamHI site of lambda EMBL3. Seventeen lambda recombinants, selected by chromosome walking, were found to contain overlapping fragments of the entire chloroplast genome. These clones were mapped using single and double digests of BamHI, EcoRI and HindIII. cDNAs synthesized from isolated 16S and 23S chloroplast rRNAs were used to map the ribosomal RNA genes relative to physical maps of the above restriction enzymes. The mapped positions of the rRNA genes for the safflower chloroplast DNA are in good agreement with previously published data for tobacco, spinach and several other higher plants.
Asunto(s)
Cloroplastos , Plantas/genética , ARN Ribosómico 16S/genética , ARN Ribosómico 23S/genética , Bacteriófago lambda/genética , Southern Blotting , Paseo de Cromosoma , Clonación Molecular , ADN/metabolismo , Enzimas de Restricción del ADN/metabolismo , Biblioteca de Genes , Operón , Mapeo RestrictivoRESUMEN
The nucleotide sequence of the Bacillus anthracis edema factor (EF) gene (cya), which encodes a calmodulin-dependent adenylate cyclase, has been determined. EF is part of the tripartite protein exotoxin of B. anthracis. An ATG start codon, immediately upstream from codons which specify the first 15 amino acids (aa) of EF, was preceded by an AAAGGAGGT sequence which is its probable ribosome-binding site. Starting at this ATG codon, there was a continuous 2400-bp open reading frame which encodes the 800-aa EF-precursor protein with a Mr of 92,464. The mature, secreted protein (767 aa; Mr 88,808) was preceded by a 33-aa signal peptide which has characteristics in common with leader peptides for other secreted proteins of the Bacillus species. A consensus amino acid sequence (Gly-X-X-X-X-Gly-Lys-Ser,X = any aa), which was part of the presumed ATP binding site for EF, was also present. The codon usage of the EF gene reflected the high A + T (71%) base composition for its DNA. B. anthracis EF was not related to the Escherichia coli or yeast adenylate cyclases, but was related to the Bordetella pertussis calmodulin-dependent adenylate cyclase.
Asunto(s)
Antígenos Bacterianos , Bacillus anthracis/genética , Toxinas Bacterianas/genética , Genes Bacterianos , Genes , Secuencia de Aminoácidos , Animales , Carbunco/microbiología , Bacillus anthracis/enzimología , Secuencia de Bases , Codón/genética , Datos de Secuencia Molecular , Biosíntesis de Proteínas , Secuencias Reguladoras de Ácidos Nucleicos , Mapeo Restrictivo , Transcripción GenéticaRESUMEN
TIS genes are rapidly and transiently induced by tetradecanoyl phorbol acetate in 3T3 cells. We analyzed the developmental appearance of a number of the TIS genes to determine whether, in a normal physiological context, these genes have common or distinct mechanisms of regulation. Each TIS gene has a distinct tissue specificity and/or developmental profile.
Asunto(s)
Regulación de la Expresión Génica/efectos de los fármacos , Ratones/embriología , Acetato de Tetradecanoilforbol/farmacología , Animales , Northern Blotting , Ratones/genética , Distribución TisularRESUMEN
The Bacillus anthracis exotoxin is composed of a lethal factor, a protective antigen, and an edema factor (EF). EF is a calmodulin-dependent adenylate cyclase which elevates cyclic AMP levels within cells. The entire EF gene (cya) has been cloned in Escherichia coli, but EF gene expression by its own B. anthracis promoter could not be detected in E. coli. However, when the EF gene was placed downstream from the lac or the T7 promoter, enzymatically active EF was produced. The EF gene, like the protective antigen (pag) and lethal factor (lef) genes, was present on the large B. anthracis toxin plasmid pXO1.