A Sophisticated Riboswitch

Science's STKE  12 Oct 2004:
Vol. 2004, Issue 254, pp. tw369
DOI: 10.1126/stke.2542004tw369

RNA gene control elements, or "riboswitches," can regulate gene expression in ways that were once thought to be the domain of proteins. Mandal et al. (see the Perspective by Famulok) now show that adjacent RNA motifs cooperatively bind two molecules of glycine in Bacillus subtilis and turn on an operon involved in glycine cleavage. The level of cooperativity per binding site produces a switch that is sensitive to very small changes in glycine concentration. The riboswitch controls genes responsible for shunting the carbon from excess glycine into the citric acid cycle.

M. Mandal, M. Lee, J. E. Barrick, Z. Weinberg, G. M. Emilsson, W. L. Ruzzo, R. R. Breaker, A glycine-dependent riboswitch that uses cooperative binding to control gene expression in bacteria. Science 306, 275-279 (2004). [Abstract] [Full Text]

M. Famulok, RNAs turn on in tandem. Science 306, 233-234 (2004). [Summary] [Full Text]