Staphylococcus aureus Transcriptome Architecture: From Laboratory to Infection-Mimicking Conditions

Area of Science:

• Microbiology
• Molecular Biology
• Genomics

Background:

• Staphylococcus aureus is a prevalent human pathogen capable of adapting to diverse environments.
• Understanding its transcriptional regulation is crucial for developing new therapeutic strategies.

Purpose of the Study:

• To comprehensively investigate the transcriptional landscape of S. aureus HG001 under various growth conditions.
• To identify and characterize transcription units, non-coding RNAs, and promoter elements.
• To explore the role of alternative sigma factors and Rho-dependent termination in gene expression regulation.

Main Methods:

• Genome-wide transcriptional profiling of S. aureus HG001.
• Promoter analysis and classification based on sigma factor dependence (SigA, SigB).
• Identification and quantification of non-coding RNAs, including antisense RNAs.
• Comparative analysis with Bacillus subtilis.
• Investigation of Rho-dependent transcription termination.

Main Results:

• An extensive catalog of transcription units and non-coding RNAs was established.
• 1412 promoters were classified based on their reliance on SigA or SigB.
• A low abundance of antisense RNAs (overlapping 6% of coding genes) was observed in S. aureus.
• Rho-dependent termination was found to suppress spurious transcription in the A+T-rich genome.
• New potential targets for known transcription factors were identified.

Conclusions:

• S. aureus exhibits a unique transcriptional regulatory system with limited antisense RNA prevalence.
• Alternative sigma factors appear to have a less significant role in S. aureus compared to B. subtilis.
• Rho-dependent termination is essential for mitigating the effects of spurious transcription in S. aureus.
• This study provides valuable genome-wide insights into S. aureus transcriptional regulation and non-coding RNA biology.