Vectors for regulated gene expression in the radioresistant bacterium Deinococcus radiodurans

Area of Science:

• Microbiology
• Molecular Biology
• Genetics

Background:

• Deinococcus radiodurans exhibits remarkable resistance to DNA damage.
• Understanding its repair mechanisms is crucial for fundamental and applied research.
• Existing tools for functional analysis in D. radiodurans are limited.

Purpose of the Study:

• To develop novel genetic vectors for regulated gene expression in D. radiodurans.
• To enable functional genomics and the study of DNA repair pathways.
• To create tools for conditional gene inactivation.

Main Methods:

• Adaptation and implementation of the IPTG-regulated Spac system (Pspac promoter and lacI repressor) from Bacillus subtilis into D. radiodurans.
• Construction of vectors for regulated expression of reporter genes (lacZ) and essential repair proteins (RecA).
• Development of systems for conditional gene inactivation using inducible promoters.

Main Results:

• The Spac system effectively controlled lacZ gene expression over two orders of magnitude based on inducer concentration and lacI copy number.
• Regulated expression of RecA conferred a conditional mitomycin-resistant phenotype.
• Conditional gene inactivation systems were successfully demonstrated, exemplified by a gyrA mutant exhibiting a conditional lethal phenotype.

Conclusions:

• The developed Spac-based vectors provide a robust system for regulated gene expression in D. radiodurans.
• These tools are valuable for dissecting gene function, particularly in DNA repair and survival mechanisms.
• The creation of conditional mutants opens new avenues for studying essential genes in D. radiodurans.