Beyond the Limits: tRNA Array Units in Mycobacterium Genomes

Area of Science:

• Genomics
• Microbiology
• Bioinformatics

Background:

• Transfer RNA (tRNA) array units, regions with high tRNA gene density, were primarily identified in a few bacterial phyla like Firmicutes.
• Their presence and organization in other bacterial genera, particularly Mycobacterium, remained largely unexplored.

Purpose of the Study:

• To identify and characterize tRNA array units within genomes associated with the Mycobacterium genus.
• To develop and apply a bioinformatics tool for detecting tRNA gene arrangement as array units.

Main Methods:

• Development and application of an in-house Perl script for identifying tRNA array units.
• Analysis of 7,670 Mycobacterium genomes, 4,312 mycobacteriophage genomes, and 40 mycobacteria plasmids.
• Identification of other non-coding RNA species within these regions.

Main Results:

• tRNA array units are abundant and diverse in Mycobacterium-associated genomes, including chromosomes, prophages, and plasmids.
• These structures are particularly prevalent in Mycobacterium abscessus complex species.
• Other non-coding RNAs, such as tmRNA and structured RNA, were also found in these regions.

Conclusions:

• tRNA array units are not restricted to a few bacterial phyla, as previously assumed, but are widespread in diverse bacterial genera like Mycobacterium.
• The presence of tRNA array units in mobile genetic elements (plasmids, bacteriophages) suggests a role in horizontal gene transfer and bacterial adaptation.
• The developed bioinformatics tool facilitates further exploration of tRNA array units in large genomic datasets.