Skip to main content
. Author manuscript; available in PMC: 2011 Jan 17.
Published in final edited form as: Mol Cell. 2007 Sep 21;27(6):859–860. doi: 10.1016/j.molcel.2007.09.002

Figure 1.

Figure 1

Role of the M-box aptamer in the transcriptional regulation of Bacillus subtilis mgtE gene. When Mg(II) levels are sub-optimal, transcription proceeds through the leader region RNA an into the mgtE structural gene. This process involves a stem-loop structure in which an anti-terminator element prevents formation of a transcription terminator. When Mg(II) levels are sufficient, the anti-terminator is instead sequestered into the stably folded structure of the M box aptamer, thereby allowing formation of a transcription terminator. The atomic structure reveals six bound Mg(II) ions in the folded M box aptamer that are implicated in this regulatory transition.