Читать книгу The New Microbiology - Pascale Cossart - Страница 16

The RNAIII of S. aureus is regulated by quorum sensing, which means it is expressed once the bacterial population reaches a certain threshold. RNAIII controls the expression of a certain number of virulence factors. It impedes the translation of proteins, such as protein A, expressed on the surface of the bacterium or secreted during the beginning of an infection. It also impedes the translation of transcription regulators such as RotA. However, it activates the expression of the toxin known as alpha-hemolysin (Hla) by acting as an antisense that allows the corresponding RNA to be translated. Additionally, RNAIII codes for the small Hld protein, another toxin of 26 amino acids. The 514-nucleotide-long RNAIII in S. aureus is a very active molecule and thus can regulate many facets of bacterial physiology over the course of an infection.