RESUMO
The 2,272,351-base pair genome of Neisseria meningitidis strain MC58 (serogroup B), a causative agent of meningitis and septicemia, contains 2158 predicted coding regions, 1158 (53.7%) of which were assigned a biological role. Three major islands of horizontal DNA transfer were identified; two of these contain genes encoding proteins involved in pathogenicity, and the third island contains coding sequences only for hypothetical proteins. Insights into the commensal and virulence behavior of N. meningitidis can be gleaned from the genome, in which sequences for structural proteins of the pilus are clustered and several coding regions unique to serogroup B capsular polysaccharide synthesis can be identified. Finally, N. meningitidis contains more genes that undergo phase variation than any pathogen studied to date, a mechanism that controls their expression and contributes to the evasion of the host immune system.
Assuntos
Genoma Bacteriano , Neisseria meningitidis/genética , Neisseria meningitidis/patogenicidade , Análise de Sequência de DNA , Variação Antigênica , Antígenos de Bactérias/imunologia , Bacteriemia/microbiologia , Cápsulas Bacterianas/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/fisiologia , Elementos de DNA Transponíveis , Evolução Molecular , Fímbrias Bacterianas/genética , Humanos , Meningite Meningocócica/microbiologia , Infecções Meningocócicas/microbiologia , Dados de Sequência Molecular , Mutação , Neisseria meningitidis/classificação , Neisseria meningitidis/fisiologia , Fases de Leitura Aberta , Óperon , Filogenia , Recombinação Genética , Sorotipagem , Transformação Bacteriana , Virulência/genéticaRESUMO
The kingdom Crenarchaeota is now known to include archaea which inhabit a wide variety of low-temperature environments. We report here lipid analyses of nonthermophilic crenarchaeotes, which revealed the presence of cyclic and acyclic dibiphytanylglycerol tetraether lipids. Nonthermophilic crenarchaeotes appear to be a major biological source of tetraether lipids in marine planktonic environments.
Assuntos
Crenarchaeota/química , Lipídeos/análise , Animais , Plâncton/química , RNA Ribossômico/análiseRESUMO
[This corrects the article on p. 1136 in vol. 64.].