Important role of the nucleotide excision repair pathway in Mycobacterium smegmatis in conferring protection against commonly encountered DNA-damaging agents.
Mycobacteria are an important group of human pathogens. Although the DNA repair mechanisms in mycobacteria are not well understood, these are vital for the pathogen's persistence in the host macrophages. In this study, we generated a null mutation in the uvrB gene of Mycobacterium smegmatis to allow us to compare the significance of the nucleotide excision repair (NER) pathway with two important base excision repair pathways, initiated by uracil DNA glycosylase (Ung) and formamidopyrimidine DNA glycosylase (Fpg or MutM), in an isogenic strain background. The strain deficient in NER was the most sensitive to commonly encountered DNA-damaging agents such as UV, low pH, reactive oxygen species, hypoxia, and was also sensitive to acidified nitrite. Taken together with previous observations on NER-deficient M. tuberculosis, these results suggest that NER is an important DNA repair pathway in mycobacteria.
Kurthkoti
Krishna
K
Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India.
Kumar
Pradeep
P
Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India.
Jain
Ruchi
R
Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India.
Varshney
Umesh
U
Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India.