RESUMO
We report on the sequence of the Methanothermus sociabilis aladh gene, which encodes the 5'-aminolevulinic acid dehydratase. The identity of the enzyme was determined by sequence comparison and by expression in Escherichia coli.
Assuntos
Euryarchaeota/genética , Sintase do Porfobilinogênio/genética , Sequência de Aminoácidos , Sequência de Bases , DNA Bacteriano , Dados de Sequência MolecularRESUMO
The genes (slgA) encoding the surface-layer glycoproteins of the hyperthermophilic methanogens Methano-thermus pervidus and Methanothermus sociabilis were cloned and sequenced. The nucleotide sequences of these genes differ at only nine positions, resulting in three amino acid differences. In both organisms, the transcription start site was localized by primer extension analyses. The DNA sequence at this site conforms to the promotor box B motif for promotors of archaea. 24 nucleotides upstream of the transcription start is an A + T-rich region, which closely resembles the consensus box A motif of promoters of methanogens. Ribosome binding sites are exactly complementary to the 3' end of the 16S rRNA of these methanogens. Both slgA genes encode for a precursor of the mature surface-layer protein containing 593 amino acid residues with a putative N-terminal signal sequence of 22 amino acid residues. The deduced protein sequences contain 20 sequon structures representing possible carbohydrate-binding sites. In comparison with other surface-layer proteins, these obtained from the two hyperthermophilic methanogens contain unusually high amounts of isoleucine, asparagine and cysteine residues. Predicted secondary structures have a high content of beta-sheet structure (44%) and only 7% alpha-helix structures.
Assuntos
Euryarchaeota/metabolismo , Glicoproteínas de Membrana/genética , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Sequência de Bases , DNA Bacteriano/genética , Eletroforese em Gel de Ágar , Dados de Sequência Molecular , Plasmídeos , Regiões Promotoras Genéticas , RNA Bacteriano/metabolismo , RNA Ribossômico 16S/metabolismo , Mapeamento por Restrição , Ribossomos/metabolismo , Transcrição GênicaRESUMO
A questionnaire was sent to the parents of 1000 3- to 7-year-old children in and around Munich whose teeth we had examined. We inquired as to the oral hygiene and the socioeconomic conditions. The def and DMF mean values were evaluated according to the age group. The results indicate that the condition of the teeth of our young people can only be improved if measures for dental hygiene and caries prophylaxis in general are intensified and improved at the kindergarten level.
