Polishing the Sxy manuscript

We're fixing the final details on the Sxy manuscript; I'm hoping to have it submitted in the next 24 hours. Below I'll try to summarize what it says, in less technical terms than the Abstract uses.

We already know that the Sxy protein regulates expression of competence genes; here we're examining how Sxy itself is regulated. Our most powerful tools are regulatory mutations that turn Sxy on when it would otherwise be off. The paper starts by describing new mutations that, taken all together, strongly suggest that expression is controlled by changes in RNA folding. We conclude this because all of the mutations change how RNA can fold, but only one of them changes the Sxy protein sequence (and that in a trivial way).

The paper then presents data showing that the RNA folding changes don't affect how much Sxy RNA is made, but how efficiently the RNA is used to make Sxy protein. Then more data shows that normal cells translate their Sxy RNA more efficiently when they're starved, but the mutant cells translate it efficiently even when they're not starved.

The cell uses the genes/proteins that Sxy regulates to take up DNA, so these results help us understand how being starved causes cells to take up DNA. We have argued that cells take up DNA as food (not to get different versions of their genes as others have assumed), so these results strengthen the evidence that DNA uptake is an adaptive response to starvation.