2bnl
From Proteopedia
The structure of the N-terminal domain of RsbR
Structural highlights
Function[RSBRA_BACSU] Acts as a positive regulator of sigma-B activity in response to salt and heat stress by stimulating the activity of the RsbT kinase toward RsbS in vitro. One of 4 functionally non-identical RsbR paralogs, it functions in the environmental signaling branch of the general stress response. Negative regulator of sigma-B activity. Non-phosphorylated RsbS binds to RsbT, preventing its association with RsbU. Requires any one of RsbRA, RsbRB, RsbRC or RsbRD to sequester RsbT. When RsbS and the RsbR paralog(s) are phosphorylated, they release RsbT, which can then bind and activate RsbU. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedRsbR is a regulator of sigma(B), the RNA polymerase sigma factor subunit responsible for transcribing the general stress response genes when environmental stress is imposed on Bacillus subtilis. The C-terminal domain of RsbR and its paralogues is a substrate for the kinase function of another sigma(B) regulator, RsbT, but the amino acid sequence of the N-terminal domain of RsbR does not reveal any obvious biochemical function. RsbR, its paralogues, and other regulators of sigma(B), including RsbS and RsbT, form large signaling complexes, called stressosomes. We have determined and present here the crystal structure of the N-terminal domain of RsbR. Unexpectedly, this structure belongs to the globin fold superfamily, but there is no bound cofactor. The globin domain from globin-coupled sensory systems replaces the N-terminal domain of RsbR in some bacteria, indicating a common genetic ancestry for RsbR and the globin family. We suggest that the globin fold has been "recycled" in RsbR and that one more activity can be included in the repertoire of globin functions, namely the ability to bind signaling macromolecules such as RsbT. Structure of a nonheme globin in environmental stress signaling.,Murray JW, Delumeau O, Lewis RJ Proc Natl Acad Sci U S A. 2005 Nov 29;102(48):17320-5. Epub 2005 Nov 21. PMID:16301540[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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