Methyltransferase DnmA is responsible for genome-wide N6-methyladenosine modifications at non-palindromic recognition...

Area of Science:

• Molecular Biology
• Epigenetics
• Genomics

Background:

• DNA methylation is a fundamental epigenetic mechanism across all domains of life.
• In bacteria, DNA methylation is known to be involved in restriction-modification systems.
• The role of N6-methyladenine (m6A) in epigenetic regulation of cellular functions in Gram-positive bacteria remains less understood.

Purpose of the Study:

• To characterize site-specific m6A modifications in Bacillus subtilis.
• To identify the methyltransferase responsible for m6A in B. subtilis.
• To investigate the functional role of m6A in bacterial gene expression and cellular processes.

Main Methods:

• Genome-wide analysis of m6A modifications in Bacillus subtilis.
• Identification and characterization of the methyltransferase gene (yeeA).
• Reporter assays to assess the impact of m6A on promoter activity and gene expression.

Main Results:

• The yeeA gene was identified as the methyltransferase responsible for m6A modifications in B. subtilis.
• m6A modification by YeeA does not limit DNA uptake during natural transformation.
• Loss of m6A in promoter regions led to decreased reporter gene expression, suggesting a role in gene activation.
• A transcriptional repressor was found to preferentially bind unmethylated promoter sequences.

Conclusions:

• N6-methyladenine (m6A) modifications in Bacillus subtilis, mediated by the YeeA methyltransferase, function to promote gene expression.
• m6A epigenetic marks in bacteria can influence transcriptional regulation beyond restriction-modification systems.
• These findings highlight a novel epigenetic regulatory role for m6A in Gram-positive bacteria.