Figure 7
Schematic diagram summarizing the positive feedback between MucE and AlgU and their relationship to alginate overproduction. AlgU is an alternative sigma factor that controls the alginate biosynthetic operon. Additionally, AlgU regulates itself, as well as drives transcription of mucE. MucE has the C-terminal –WVF motif that can activate the protease AlgW, thereby causing the degradation of the anti-sigma factor MucA. The degradation of MucA results in the release of AlgU to activate transcription at the PalgU, P algD  and P mucE  promoter sites.