Extended Data Figure 2: Purification and negative-stain electron microscopy analyses of the TssJLM–TssA complex.
From: Priming and polymerization of a bacterial contractile tail structure
a, TssA interacts with the TssJM complex. The total solubilized membrane extract (T) of 4 × 109 cells producing the indicated proteins was subjected to affinity chromatography using streptactin resin. Bound proteins (E) were separated by SDS–PAGE and immunodetected with anti-Flag (TssA and TssL), anti-strep tag (TssJ) and anti-5×His (TssM) monoclonal antibodies. The molecular weight markers are indicated on the left. The uncropped scans of the western blots are provided in Supplementary Figure 1. b, Superose 6 10/300 gel-filtration profile of the purified TssJLM–TssA complex. The asymmetry of the peak probably reflects the co-purification of different complexes or the dissociation of TssA from the TssJLM complex. c, Examples of representative raw particles observed for the purified TssJLM–TssA complex sample using negative-stain electron microscopy. A typical TssJLM complex is shown in red (number of particles observed n = 240) whereas a TssA-bound TssJLM complex is shown in white (n = 95). Scale bar is 10 nm. d, Magnification of the two complexes shown in c. Scale bars, 10 nm.
