L-box

The L-box is a [wiki|riboswitch] that binds lysine and controls gene expression by a termination/ antitermination mechanism. Upon binding of lysine, the L-box adopts a terminator structure thus preventing expression of [gene|F7B947938FB40E54D89A719E9610C5A4AA400674|lysC]. In the absence of lysine, the L-box has an antiterminator structure that allows [gene|F7B947938FB40E54D89A719E9610C5A4AA400674|lysC] expression and thus lysine biosynthesis.

[wiki|RNA switch]