DNA as a nutrient: novel role for bacterial competence gene homologs.
The uptake and stable maintenance of extracellular DNA, genetic transformation, is universally recognized as a major force in microbial evolution. We show here that extracellular DNA, both homospecific and heterospecific, can also serve as the sole source of carbon and energy supporting microbial growth. Mutants unable to consume DNA suffer a significant loss of fitness during stationary-phase competition. In Escherichia coli, the use of DNA as a nutrient depends on homologs of proteins involved in natural genetic competence and transformation in Haemophilus influenzae and Neisseria gonorrhoeae. Homologs of these E. coli genes are present in many members of the gamma subclass of Proteobacteria, suggesting that the mechanisms for consumption of DNA may have been widely conserved during evolution.
Finkel
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Department of Biological Sciences, University of Southern California, Los Angeles, California 90089-1340, USA. sfinkel@usc.edu
Kolter
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D015169:Colony Count, Microbial; D003470:Culture Media; D017077:Culture Media, Conditioned; D004269:DNA, Bacterial / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D019143:Evolution, Molecular; D020563:Gammaproteobacteria / Q000235:genetics; D005798:Genes, Bacterial; D006193:Haemophilus influenzae / Q000235:genetics; D009154:Mutation; D017386:Sequence Homology, Amino Acid; D014169:Transformation, Bacterial
D003470:Culture Media; D017077:Culture Media, Conditioned; D004269:DNA, Bacterial