From the paper by Blattner et al.5, the proportion of genes in Escherichia coli that are dedicated to known functions is estimated. Importantly, 30-40 per cent of genes have no known function, and are not obviously related to genes of known function. So what do they do? It is generally accepted that by conventional biochemistry and genetics we have identified most (perhaps 80 per cent) of the genes that are required for the biochemical and regulatory pathways necessary for the normal life of the E. coli cell: it seems unlikely that all these ‘orphan’ genes will be required to fill in the ‘gaps’. Perhaps the unidentified genes serve complex functions, such as: • Survival in unusual environments, or within host cells • Integrating and coordinating the known metabolic pathways • Organizing the chromosome, replication and transcription within the confined space of the cell • Creating local environments within the cell • Memory or communication
Finally, we should not discount the possibility that although these orphan genes may not encode a communication system with Alpha Centauri, they may yet yield surprises.
References
Hale, T. L.et al. Infect. Immun. 40, 340–350 (1983).
Riley, L. W.et al. N. Engl. J. Med. 308, 681–685 (1983).
Cross, A. S.et al. J. Infect. Dis. 149, 184–193 (1984).
Fleischmann, R. D. et al. Science 269, 496–512 (1995).
Blattner, F. R. et al. Science 277, 1453–1461 (1997).
Schaechter, M. & Neidhardt, F. C. in Escherichia coli and Salmonella typhimurium (eds Neidhardt, F. C. et al.) 1-2 (ASM, Washington, 1987).
Neidhardt, F. C. et al.(eds) Escherichia coli and Salmonella 2nd edn (ASM, Washington, 1996).
Cairns, J., Stent, G. S. & Watson, J. D. (eds) Phage and the Origins of Molecular Biology (Cold Spring Harbor, New York, 1966).
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Moxon, E., Higgins, C. Functions for orphan genes. Nature 389, 120 (1997). https://doi.org/10.1038/38110
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DOI: https://doi.org/10.1038/38110
