RNase III-Binding-mRNAs Revealed Novel Complementary Transcripts in Streptomyces.

Area of Science:

• Microbiology
• Molecular Biology
• Genetics

Background:

• Antisense RNAs (asRNAs) offer precise gene regulation through complementary binding.
• The role of asRNAs in the complex development of antibiotic-producing Streptomyces remains largely unknown.
• RNase III, a double-strand-specific endoribonuclease, interacts with numerous Streptomyces mRNAs.

Purpose of the Study:

• To investigate the presence and expression of asRNAs targeting mRNAs previously identified to interact with RNase III in Streptomyces.
• To characterize novel asRNAs and their potential roles in Streptomyces gene regulation and development.

Main Methods:

• Rapid Amplification of cDNA Ends (RACE) mapping to identify asRNA transcripts.
• Northern blotting to analyze the expression profiles of novel transcripts.
• Testing for antisense expression in the presence and absence of RNase III.

Main Results:

• All 17 tested mRNAs co-precipitated with RNase III were found to possess cognate asRNAs.
• Several novel asRNAs were identified, including as-adpA, as-rnc, as3983, as-sigB, as-sigH, and as-sigR.
• Only a small fraction of asRNAs showed increased expression in the absence of RNase III.

Conclusions:

• Antisense RNA-mediated gene regulation is a widespread mechanism in Streptomyces.
• asRNAs regulate genes involved in critical processes, including developmental regulation (e.g., AdpA) and essential enzymes (e.g., RNase III, sigma factors).