Fig. 7.

PTex recovers bacterial RNPs. a Salmonella Typhimurium SL1344 Hfq-FLAG was UV-cross-linked and HOT-PTex was performed to purify bacterial RNPs. b Western blot using an anti-FLAG antibody demonstrates recovery of Hfq monomers linked to RNA. Note that the physiologically active Hfq hexamer partially withstands SDS-PAGE conditions⁴⁹ and that this complex is also enriched after PTex. c RNPs in Salmonella were purified by PTex globally. 172 Proteins enriched after UV-cross-linking (PTex CL) contain ribosomal proteins (transparent red), known RBPs (red) and DNA-binders (orange). Individual enriched proteins not known to associate with RNA before were used for validation (in parentheses). d Validation of PTex-enriched RNA-interactors: Salmonella strains expressing FLAG-tagged proteins were immunoprecipitated  ±UV irradiation. RNA-association is confirmed by radioactive labelling of RNA 5′ ends by polynucleotide kinase (T4 PNK) using autoradiography; a signal is exclusively detectable after UV-cross-linking and radiolabelling of precipitated RNA. CsrA-FLAG (pos. ctr.), YigA-FLAG (neg. ctr.), AhpC-FLAG, SipA-FLAG and YihI-FLAG are bound to RNA in vivo. e GO terms significantly enriched among the RNA-associated proteins; p-value derived from a one-tail Fisher Exact test⁷⁵. For full gels/blots see Supplementary Figures 25, 26