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Phospho‐dependent signaling during the general stress response by the atypical response regulator and ClpXP adaptor RssB
Author(s) -
Schwartz Jacob,
Son Jonghyeon,
Brugger Christiane,
Deaconescu Alexandra M.
Publication year - 2021
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1002/pro.4047
Subject(s) - signal transducing adaptor protein , regulator , response regulator , proteolysis , biology , rpos , microbiology and biotechnology , signal transduction , genetics , biochemistry , bacterial protein , promoter , gene expression , enzyme , bacteria , gene
In the model organism Escherichia coli and related species, the general stress response relies on tight regulation of the intracellular levels of the promoter specificity subunit RpoS. RpoS turnover is exclusively dependent on RssB, a two‐domain response regulator that functions as an adaptor that delivers RpoS to ClpXP for proteolysis. Here, we report crystal structures of the receiver domain of RssB both in its unphosphorylated form and bound to the phosphomimic BeF 3 − . Surprisingly, we find only modest differences between these two structures, suggesting that truncating RssB may partially activate the receiver domain to a “meta‐active” state. Our structural and sequence analysis points to RssB proteins not conforming to either the Y–T coupling scheme for signaling seen in prototypical response regulators, such as CheY, or to the signaling model of the less understood FATGUY proteins.