Protection of DNA during starvation. Dps is a histone-like protein induced in response to starvation that appears to protect DNA from oxidative damage, particularly that caused by hydrogen peroxide. Dps binds DNA with high affinity but without any apparent sequence specificity. In doing so Dps does not interfere with transcription but does reduce the amount of oxidative damage observed. Crystals of Dps have been obtained and the three-dimensional structure of the protein should be solved in the near future. This structure should allow for the modeling of how Dps binds DNA and protects it.
Metabolic signals of starvation. Recent findings from the laboratory indicate that bacteria sense starvation by means of generating a signal molecule as a result of metabolic imbalance. Specifically, homoserine lactone has been shown to be critical as a metabolite that accumulates in response to starvation that signals global changes in gene expression. The discovery of this signal molecule involved in starvation comes to unify the fields of bacterial starvation with cell-cell communication, which is mediated by acylated derivatives of homoserine lactone.
Selected Publications:
Huisman, G. and Kolter, R. (1994). Sensing starvation: a homoserine lactone dependent signaling pathway in E. coli. Science 265:537-539.
Altuvia, S., Almirón, M., Huisman, G., Kolter, R. and Storz, G. (1994). The dps promoter is activated by OxyR during growth and by IHF and ss in stationary phase. Molec. Microbiol. 13:265-272.
Babbitt, P.C., Mrachko, G.T., Hasson, M.S., Huisman, G.W., Kolter, R., Ringe, D., Petsko, G.A., Kenyon, G.L. and Gerlt, J.A. (1995). A functionally diverse enzyme superfamily that abstracts the a-protons of carboxylic acids. Science 267:1159-1161.