Sigma-E is important for the induction of proteins involved in heat shock response. RseA binds sigma-E via its N-terminal domain, sequestering sigma-E and preventing transcription from heat-shock promoters [1]. The C-terminal domain is located in the periplasm, and may interact with other protein that signal periplasmic stress.

1: The sigmaE-mediated response to extracytoplasmic stress in Escherichia coli is transduced by RseA and RseB, two negative regulators of sigmaE. De Las Penas A, Connolly L, Gross CA; Mol Microbiol 1997;24:373-385. PMID:9159523