title: DNA metabolism in mycobacterial pathogenesis.
abstract: Fundamental aspects of the lifestyle of Mycobacterium tuberculosis implicate DNA metabolism in bacillary survival and adaptive evolution. The environments encountered by M. tuberculosis during successive cycles of infection and transmission are genotoxic. Moreover, as an obligate pathogen, M. tuberculosis has the ability to persist for extended periods in a subclinical state, suggesting that active DNA repair is critical to maintain genome integrity and bacterial viability during prolonged infection. In this chapter, we provide an overview of the major DNA metabolic pathways identified in M. tuberculosis, and situate key recent findings within the context of mycobacterial pathogenesis. Unlike many other bacterial pathogens, M. tuberculosis is genetically secluded, and appears to rely solely on chromosomal mutagenesis to drive its microevolution within the human host. In turn, this implies that a balance between high versus relaxed fidelity mechanisms of DNA metabolism ensures the maintenance of genome integrity, while accommodating the evolutionary imperative to adapt to hostile and fluctuating environments. The inferred relationship between mycobacterial DNA repair and genome dynamics is considered in the light of emerging data from whole-genome sequencing studies of clinical M. tuberculosis isolates which have revealed the potential for considerable heterogeneity within and between different bacterial and host populations.
authors: MRC/NHLS/UCT Molecular Mycobacteriology Research Unit and DST/NRF Centre of Excellence for Biomedical TB Research, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, P/Bag X3, Rondebosch, 7700, South Africa, digby.warner@uct.ac.za.
authors: Digby F
authors: DF
authors: Warner
authors: Tone
authors: T
authors: Tønjum
authors: Valerie
authors: V
authors: Mizrahi
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D004260:DNA Repair; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism*; D018740:Genetic Heterogeneity; D016680:Genome, Bacterial; D059014:High-Throughput Nucleotide Sequencing; D054884:Host-Pathogen Interactions; D006801:Humans; D016296:Mutagenesis; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity*; D011995:Recombination, Genetic; D014397:Tuberculosis, Pulmonary / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial