The conserved noncoding RNA ModT coordinates growth and virulence in Clostridioides difficile.

Area of Science:

• Bacterial molecular biology
• RNA biology
• Microbial physiology

Background:

• Bacterial noncoding RNAs are crucial for diverse cellular functions, often relying on complex tertiary structures.
• The conserved "raiA motif" RNA in bacteria, particularly in Bacillota and Actinomycetota, plays a significant role.

Purpose of the Study:

• To characterize the function and mechanism of the conserved "raiA motif" RNA in Clostridioides difficile.
• To investigate its role in bacterial growth transitions and stationary phase processes.

Main Methods:

• RNA transcript abundance and stability analysis.
• Gene deletion mutant construction and phenotypic analysis (growth, sporulation).
• In vivo chemical structure probing and cross-species complementation assays.

Main Results:

• The "raiA motif" RNA, renamed ModT, is highly abundant and stable, comparable to ribosomal RNAs.
• ModT deletion causes delayed entry into stationary phase and impairs spore formation.
• ModT influences cyclic di-GMP levels, linking it to sporulation defects; orthologs show conserved function.

Conclusions:

• ModT is a conserved bacterial RNA essential for regulating the transition to stationary phase and sporulation.
• Its mechanism involves modulating cyclic di-GMP levels, with conserved cross-species functionality.
• Further research into ModT's structure and protein interactions is warranted to fully elucidate its mechanism.