RESUMO
The RPC31 gene encoding the C31 subunit of Saccharomyces cerevisiae RNA polymerase C (III) has been isolated, starting from a C-terminal fragment cloned on a lambda gt11 library. It is unique on the yeast genome and lies on the left arm of chromosome XIV, very close to a NotI site. Its coding sequence perfectly matches the amino acid sequence of two oligopeptides prepared from purified C31. It is also identical to the ACP2 gene previously described as encoding an HMG1-like protein (W. Haggren and D. Kolodrubetz, Mol. Cell. Biol. 8:1282-1289, 1988). Thus, ACP2 and RPC31 are allelic and encode a subunit of RNA polymerase C. The c31 protein has a highly acidic C-terminal tail also found in several other chromatin-interacting proteins, including animal HMG1. Outside this domain, however, there is no appreciable homology to any known protein. The growth phenotypes of a gene deletion, of insertions, and of nonsense mutations indicate that the C31 protein is strictly required for cell growth and that most of the acidic domain is essential for its function. Random mutagenesis failed to yield temperature-sensitive mutants, but a slowly growing mutant was constructed by partial suppression of a UAA nonsense allele of RPC31. Its reduced rate of tRNA synthesis in vivo relative to 5.8S rRNA supports the hypothesis that the C31 protein is a functional subunit of RNA polymerase C.
Assuntos
RNA Polimerases Dirigidas por DNA/genética , Genes Fúngicos , RNA Polimerase III/genética , Saccharomyces cerevisiae/genética , Sequência de Aminoácidos , Clonagem Molecular , DNA Fúngico/genética , DNA Fúngico/isolamento & purificação , Genótipo , Substâncias Macromoleculares , Dados de Sequência Molecular , Mutação , Plasmídeos , RNA Fúngico/genética , RNA Fúngico/isolamento & purificação , Mapeamento por Restrição , Saccharomyces cerevisiae/enzimologiaRESUMO
We prepared a cDNA library from venom glands of the green mamba Dendroaspis angusticeps. A cDNA clone was isolated using an appropriate nucleotide probe. The nucleotide sequence codes for a 21 residue signal peptide followed by a 65 residue protein having the amino acid sequence of muscarinic toxin 2, as confirmed in the accompanying paper (Karlsson, E., Risinger, C., Jolkkonen, M., Wernstedt, C. and Adem, A.). The cDNA encoding the muscarinic toxin has been compared with those encoding other snake toxins. There are close similarities with short-chain curaremimetic neurotoxins.
Assuntos
Venenos Elapídicos/química , Neurotoxinas/química , Sequência de Aminoácidos , Sequência de Bases , DNA/genética , Venenos Elapídicos/genética , Dados de Sequência Molecular , Neurotoxinas/genética , Proteínas de Répteis , Homologia de Sequência do Ácido NucleicoRESUMO
We report a case of pyometra without any related risk factor. This leads to a severe septic shock. Evolution was successful because of quick surgical management. We report literature management of such infection. Although pyometra is an uncommon disease, it should be kept in mind as delayed management may lead to fatal outcome.