All cells have a battery of DNA-repair pathways, including stress-induced DNA break repair in Escherichia coli, to help ensure genome maintenance and stability. Similar pathways—which can be mutagenic—are known in yeast and human cells and have the potential to accelerate evolution. Sixteen proteins are known to be required for the pathway in E. coli. Al Mamun et al. analyzed the E. coli pathway to determine the full complement of protein contributions to the pathway. Ninety-three genes were found to be required for stress-induced DNA break repair. One-third of the proteins identified in the network were involved in electron transfer, functioning in oxidative phosphorylation, and acting through the σs stress response pathway, which thus represents a critical hub in the network.
A. A. M. Al Mamun, M.-J. Lombardo, C. Shee, A. M. Lisewski, C. Gonzalez, D. Lin, R. B. Nehring, C. Saint-Ruf, J. L. Gibson, R. L. Frisch, O. Lichtarge, P. J. Hastings, S. M. Rosenberg, Identity and function of a large gene network underlying mutagenic repair of DNA breaks. Science 338, 1344–1348 (2012). [Abstract] [Full Text]