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. Author manuscript; available in PMC: 2013 Dec 11.
Published in final edited form as: Science. 2011 Feb 3;331(6021):10.1126/science.1201476. doi: 10.1126/science.1201476

Fig. 4. The type III secretion chaperones are required for the loading of translocases and effector protein onto the SpaO/OrgA/OrgB platform.

Fig. 4

(A) Samples from the wild-type S. Typhimurium, a mutant lacking the translocase-chaperone InvE, or a strain expressing a mutant of SptP lacking its chaperone-binding domain (SptPΔ35–161;indicated as SptPΔcbd) were prepared as indicated above and the presence of the translocases SipB, SipC and SipD and the effector protein SptP in the SpaO/OrgA/OrgB complex was examined by BN-PAGE and immuno blot analysis. A S. Typhimurium lacking SipB was used as a background strain for these experiments to enhance the detection of SipD or SptP. In all cases the left panel show the simultaneous detection of the indicated effector or translocase (green) and the needle complexes (red) and right (black and white) panels show only the channel corresponding to the detection of the respective effector or translocase proteins. Lower panels show SDS-PAGE immuno-blot analysis of the indicated proteins in equal amounts of whole cell lysates of the indicated strains. (B) Samples from wild-type S. Typhimurium, a strain expressing FLAG epitope tagged SicP, the chaperone for SptP, or a strain expressing FLAG-tagged SptP, were prepared as indicated above and separated by BN-PAGE. The left panel shows the simultaneous detection of SicPFLAG or SptPFLAG (green) and the needle complexes (red) and right (black and white) panel shows only the channel corresponding to the detection of SicPFLAG or SptPFLAG. The lower panels show SDS-PAGE immuno-blot analysis of the indicated proteins in equal amounts of whole cell lysates of the indicated strains. (C) Samples from the indicated strains were prepared as described above and separated by BN-PAGE. The left panel shows the simultaneous detection of SicPFLAG or SptP (green) and the needle complexes (red) and right (black and white) panels show only the channel corresponding to the detection of SicPFLAGor SptP.