Prg complex isolation from E. coli. (A)
SDS/PAGE of whole cell lysates (WC) and needle complex fractions (NC)
prepared from recombinant E. coli (DH5α) expressing
prgH (pTK43), prgK (pTK44), or
prgH/prgK (pTK53). (B)
Western blot analysis of PrgH isolated from E. coli
(from A). The sample was resuspended in SDS loading
buffer and boiled (+) or directly loaded (−) onto the gel. Blot was
probed with polyclonal antiserum to PrgH. (C and
D) Electron micrographs of (C) PrgH
isolated from E. coli, and (D) NC
isolated from WT S. typhimurium. In both
C and D, numerous tetrameric-shaped
structures can be seen. (Scale bar, 50 nm.) (E) Enlarged
image of one of the tetramers from C with a schematic
showing an approximate size of 10 nm × 10 nm
(n = 25). (Scale bar, 50 nm.)