Data export CSV files from HDX Workbench, software platform for the analysis of hydrogen/deuterium exchange (HDX) mass spectrometry data.

In enterobacteria such as Escherichia coli, the general stress response is mediatedby σs, the stationary phase dissociable promoter specificity subunit of RNApolymerase. σs is degraded by ClpXP during active growth in a process dependent onthe RssB adaptor, which is thought to be stimulated by phosphorylation of a conservedaspartate in its N-terminal receiver domain. Here we present the crystal structure offull-length RssB bound to a beryllofluoride phosphomimic. Compared to the structure ofRssB bound to the IraD anti-adaptor, our new RssB structure with bound beryllofluoridereveals conformational differences and coil-to-helix transitions in the C-terminal regionof the RssB receiver domain and in the inter-domain segmented helical linker. Theseare accompanied by masking of the α4-β5-α5 (4-5-5) “signaling” face of the RssBreceiver domain by its C-terminal domain. Critically, using hydrogen-deuteriumexchange mass spectrometry we identify σs binding determinants on the 4-5-5 face,implying that this surface needs to be unmasked to effect an interdomain interfaceswitch and enable full σs engagement and hand-off to ClpXP. In activated receiverdomains, the 4-5-5 face is often the locus of intermolecular interactions, but its maskingby intramolecular contacts upon phosphorylation is unusual, emphasizing that RssB isa response regulator that undergoes atypical regulation.
Files included are data export from HDX Workbench software from the HDX-MS experiments in support of this work. The files are in CSV format.