RESUMO
The Caulobacter crescentus flagellar filament is assembled from multiple flagellin proteins that are encoded by six genes. The amino acid sequences of the FljJ and FljL flagellins are divergent from those of the other four flagellins. Since these flagellins are the first to be assembled in the flagellar filament, one or both might have specialized to facilitate the initiation of filament assembly.
Assuntos
Caulobacter crescentus/genética , Flagelina/genética , Genes Bacterianos , Sequência de Aminoácidos , Sequência de Bases , DNA Bacteriano , Flagelina/classificação , Regulação Bacteriana da Expressão Gênica , Dados de Sequência Molecular , Homologia de SequênciaRESUMO
The polar organelle development gene, podJ, is expressed during the swarmer-to-stalked cell transition of the Caulobacter crescentus cell cycle. Mutants with insertions that inactivate the podJ gene are nonchemotactic, deficient in rosette formation, and resistant to polar bacteriophage, but they divide normally. In contrast, hyperexpression of podJ results in a lethal cell division defect. Nucleotide sequence analysis of the podJ promoter region revealed a binding site for the global response regulator, CtrA. Deletion of this site results in increased overall promoter activity, suggesting that CtrA is a negative regulator of the podJ promoter. Furthermore, synchronization studies have indicated that temporal regulation is not dependent on the presence of the CtrA binding site. Thus, although the level of podJ promoter activity is dependent on the CtrA binding site, the temporal control of podJ promoter expression is dependent on other factors.
Assuntos
Caulobacter crescentus/citologia , Caulobacter crescentus/genética , Proteínas de Ligação a DNA , Regulação Bacteriana da Expressão Gênica , Proteínas de Membrana/genética , Fatores de Transcrição , Proteínas de Bactérias/metabolismo , Bacteriófagos , Sequência de Bases , Sítios de Ligação , Caulobacter crescentus/virologia , Ciclo Celular , Clonagem Molecular , Genes Bacterianos , Genes Letais , Teste de Complementação Genética , Proteínas de Membrana/biossíntese , Dados de Sequência Molecular , Mutagênese Insercional , Organelas/genética , Regiões Promotoras Genéticas , Fatores de TempoRESUMO
A 62-year-old male with a 20-year history of diabetes and three-year history of adult T-cell lymphocytic leukemia developed a systemic infection with Dactylaria gallopava. At autopsy the fungus was found in the brain, lungs, liver, spleen, and kidney. The organism has caused disease in chickens and turkey poults and has been found in chicken litter, hot springs, and the effluent of a thermonuclear reactor. This report documents the second human infection and the first case of disseminated human dactylariosis.
