RESUMO
Pseudomonas aeruginosa is a ubiquitous environmental bacterium that is one of the top three causes of opportunistic human infections. A major factor in its prominence as a pathogen is its intrinsic resistance to antibiotics and disinfectants. Here we report the complete sequence of P. aeruginosa strain PAO1. At 6.3 million base pairs, this is the largest bacterial genome sequenced, and the sequence provides insights into the basis of the versatility and intrinsic drug resistance of P. aeruginosa. Consistent with its larger genome size and environmental adaptability, P. aeruginosa contains the highest proportion of regulatory genes observed for a bacterial genome and a large number of genes involved in the catabolism, transport and efflux of organic compounds as well as four potential chemotaxis systems. We propose that the size and complexity of the P. aeruginosa genome reflect an evolutionary adaptation permitting it to thrive in diverse environments and resist the effects of a variety of antimicrobial substances.
Assuntos
Genoma Bacteriano , Pseudomonas aeruginosa/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biologia Computacional , DNA Bacteriano , Resistência Microbiana a Medicamentos , Regulação Bacteriana da Expressão Gênica , Humanos , Dados de Sequência Molecular , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/patogenicidade , Pseudomonas aeruginosa/fisiologia , Análise de Sequência de DNA , Especificidade da EspécieRESUMO
We herein describe all genes encoding constituents of the phosphoenolpyruvate:sugar phosphotransferase system (PTS) in the 6Mbp genome of the opportunistic human pathogen, Pseudomonas aeruginosa. Only four gene clusters were found to encode identifiable PTS homologues. These genes clusters encode novel multidomain proteins, two complete sugar-specific PTS phosphoryl transfer chains for the metabolism of fructose and N-acetylglucosamine, and a complex regulatory system that may function to coordinate carbon and nitrogen metabolism. No previously characterized organism has been shown to exhibit such a novel and restricted complement of PTS proteins.
Assuntos
Sistema Fosfotransferase de Açúcar do Fosfoenolpiruvato/genética , Pseudomonas aeruginosa/enzimologia , Genoma Bacteriano , Humanos , Família Multigênica , Óperon , Fosfotransferases (Aceptor do Grupo Nitrogenado)/genética , Pseudomonas aeruginosa/genéticaRESUMO
Oncostatin M (OSM) and leukemia inhibitory factor (LIF) are members of a family of cytokines that regulate the proliferation and differentiation of a variety of cell types. In this report, cDNA probes specific for OSM and LIF were hybridized to DNA from somatic cell hybrids containing defined regions of human chromosome 22, and the gene for human OSM was found to segregate with that of LIF. Southern analysis of high-molecular-weight DNA that had been digested with rare-cutting restriction enzymes and analyzed by pulsed-field gel electrophoresis showed identical hybridization patterns with both probes. The probes also identified common cosmid clones on high-density cosmid filters prepared from chromosome 22-specific flow-sorted cosmid libraries. Restriction and Southern analyses of six cosmid clones established a contig of approximately 100 kb surrounding the genes for OSM and LIF. The OSM and LIF genes are tandemly arranged in the same transcriptional orientation separated by approximately 10 kb. The direction of gene transcription is telomeric to centromeric, with the OSM gene located upstream of the LIF gene. Our studies define a new gene cluster on chromosome 22 and provide strong evidence that OSM and LIF have resulted from duplication of a common ancestral gene.