RESUMO
Seven classes of Streptomyces clavuligerus mutants defective in clavulanic acid (CLA) biosynthesis have been identified and used to clone the chromosomal DNA encoding eight CLA biosynthetic genes. The complete sequences of three and the partial sequences of two of these biosynthetic genes are reported, together with their known or predicted functions.
Assuntos
Antibacterianos/biossíntese , Ácidos Clavulânicos/biossíntese , Streptococcus/genética , Acetiltransferases/genética , Sequência de Aminoácidos , Sequência de Bases , Ácido Clavulânico , Clonagem Molecular , DNA Bacteriano/genética , Genes Bacterianos , Teste de Complementação Genética , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Mapeamento por Restrição , Ureo-Hidrolases/genéticaRESUMO
The DNA of certain species of halophilic and methanogenic archaebacteria is dam methylated, as shown by restriction endonuclease sensitivities. The Dam+ phenotype appears to be confined to particular taxonomic groupings defined by DNA:rRNA hybridization or 16S RNA oligonucleotide cataloguing.
Assuntos
Archaea/genética , Bactérias/genética , Metiltransferases/genética , Archaea/classificação , Archaea/enzimologia , DNA Bacteriano , Eletroforese em Gel de Ágar , Metilação , Fenótipo , DNA Metiltransferases Sítio Específica (Adenina-Específica)RESUMO
DNA-16S rRNA hybridization studies of archaebacterial halophiles revealed nine major groups. High (greater than 45%) DNA-DNA homologies were found only within DNA-rRNA groups. The DNA-DNA homology between the type strains of Halobacterium halobium, Hb. salinarium and Hb. cutirubrum was greater than 70%. The implications for the taxonomy of the extreme halophiles are discussed.