Unique Degradation Signal for ClpCP inBacillus subtilis

Abstract

Regulation of the cell-specific transcription factor σ^F in the spore-forming bacterium Bacillus subtilis involves the antisigma factor SpoIIAB. Contributing to the activation of σ^F is the degradation of SpoIIAB in a manner that depends on the protease ClpCP. Here we show that the three residues (LCN) located at the extreme C terminus of SpoIIAB are both necessary and sufficient for this degradation. We also report that the use of the LCN extension as a degradation signal for ClpCP is unique to SpoIIAB.