Scanning iron response regulator binding sites using Dap-seq in the Brucella genome

Area of Science:

• Microbiology
• Molecular Biology
• Biochemistry

Background:

• Iron is essential for all organisms, including Brucella.
• The Iron response regulator (Irr) is a key transcriptional regulator influencing Brucella's growth and iron uptake.
• Previous research indicated Irr targets multiple genes involved in iron metabolism.

Purpose of the Study:

• To identify novel iron metabolism genes regulated by the Irr protein in Brucella.
• To investigate the interaction between Irr and its target genes.
• To elucidate the role of identified genes, particularly rirA, in Brucella's iron metabolism and growth.

Main Methods:

• Dap-seq (DNA adenine methyltransferase identification by sequencing) was employed to identify Irr target genes.
• Quantitative reverse transcription PCR (qRT-PCR) was used to analyze gene expression levels.
• Electrophoretic mobility shift assay (EMSA) confirmed protein-DNA interactions.
• Iron utilization and growth assays assessed the functional role of identified genes.

Main Results:

• Seven potential target genes of Irr were identified.
• EMSA confirmed interactions between Irr and six genes: rirA, membrane protein (BME_RS01725), hypothetical protein (BME_RS09560), ftrA, cation-transporting P-type ATPase (zntA), and 2Fe-2S binding protein (BME_RS13655).
• The rirA gene was confirmed to be involved in Brucella's iron metabolism and growth.

Conclusions:

• Six novel genes regulated by Irr, potentially involved in iron metabolism, were identified in Brucella.
• The rirA gene is a regulon of Irr and plays a significant role in Brucella iron metabolism.
• These findings offer valuable insights into the complex iron metabolism pathways in Brucella.