期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2005
卷号：102
期号：40
页码：14249-14254
DOI：10.1073/pnas.0503838102
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Small RNA (sRNA) genes are expressed in all organisms, primarily as regulators of translation and message stability. We have developed comparative genomic approaches to identify sRNAs that are expressed by Staphylococcus aureus, the most common cause of hospital-acquired infections. This study represents an in-depth analysis of the RNome of a Gram-positive bacterium. A set of sRNAs candidates were identified in silico within intergenic regions, and their expression levels were monitored by using microarrays and confirmed by Northern blot hybridizations. Two sRNAs were also detected directly from purification and RNA sequence determination. In total, at least 12 sRNAs are expressed from the S. aureus genome, five from the core genome and seven from pathogenicity islands that confer virulence and antibiotic resistance. Three sRNAs are present in multiple (two to five) copies. For the sRNAs that are conserved throughout the bacterial phylogeny, their secondary structures were inferred by phylogenetic comparative methods. In vitro binding assays indicate that one sRNA encoded within a pathogenicity island is a trans-encoded antisense RNA regulating the expression of target genes at the posttranscriptional level. Some of these RNAs show large variations of expression among pathogenic strains, suggesting that they are involved in the regulation of staphylococcal virulence.
关键词：nosocomial infections ; prokaryotes ; small regulatory noncoding RNAs
