Pseudomonas aeruginosa infection in cystic fibrosis: nucleotide sequence and transcriptional regulation of the algD gene.
Pulmonary infection by mucoid, alginate producing, Pseudomonas aeruginosa is a major complication in patients suffering from cystic fibrosis (CF). To analyze the mechanisms leading to the emergence of mucoid P. aeruginosa in CF lungs, control of the algD gene coding for GDPmannose dehydrogenase was studied. Transcriptional activation of algD was shown to be necessary for alginate production. Sequencing of algD and its promoter revealed multiple direct repeats upstream of the transcription start and throughout the promoter region. Using the algD-xy1E transcriptional fusion the algD promoter was demonstrated to be under positive control by the algR gene. This gene has previously been shown to undergo antibiotic promoted chromosomal amplification resulting in the emergence of the mucoid phenotype. These findings provide a basis for better understanding the control of mucoidy in P. aeruginosa.
D000464:Alginates / Q000096:biosynthesis*; D000595:Amino Acid Sequence; D001483:Base Sequence; D002237:Carbohydrate Dehydrogenases / Q000235:genetics*; D003550:Cystic Fibrosis / Q000382:microbiology*; D005786:Gene Expression Regulation; D005798:Genes, Bacterial; D005809:Genes, Regulator; D006801:Humans; D009690:Nucleic Acid Conformation; D011401:Promoter Regions, Genetic; D011550:Pseudomonas aeruginosa / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid; D014158:Transcription, Genetic
D000464:Alginates; D002237:Carbohydrate Dehydrogenases; C020562:GDPmannose dehydrogenase