σE, a sporulation-specific transcription factor of Bacillus subtilis, is synthesized as an inactive proprotein with a 27-amino acid extension at its amino terminus. This "pro" sequence is removed by a developmentally regulated protease, but when present, it blocks σE activity, tethers σE to the bacterium's cytoplasmic membrane, and promotes σE stability. To investigate whether pro-σE processing and/or stabilization are tied to membrane sequestration, we used fluorescent protein fusions to examine the membrane binding of SigE variants. The results are consistent with membrane association as a prerequisite for pro-σE processing but not as a sufficient cause for the proprotein's stability.
ASJC Scopus subject areas
- Molecular Biology