Weak Interactions between Salmonella enterica FlhB and Other Flagellar Export Apparatus Proteins Govern Type III Secretion Dynamics

Content Provider	Semantic Scholar
Author	McMurry, Jonathan L. Minamino, Tohru Furukawa, Yukio Francis, Joshua W. Hill, Stephanie A. Helms, Katy A. Namba, Keiichi
Copyright Year	2015
Abstract	The bacterial flagellum contains its own type III secretion apparatus that coordinates protein export with assembly at the distal end. While many interactions among export apparatus proteins have been reported, few have been examined with respect to the differential affinities and dynamic relationships that must govern the mechanism of export. FlhB, an integral membrane protein, plays critical roles in both export and the substrate specificity switching that occurs upon hook completion. Reported herein is the quantitative characterization of interactions between the cytoplasmic domain of FlhB (FlhBC) and other export apparatus proteins including FliK, FlhAC and FliI. FliK and FlhAC bound with micromolar affinity. KD for FliI binding in the absence of ATP was 84 nM. ATP-induced oligomerization of FliI induced kinetic changes, stimulating fast-on, fast-off binding and lowering affinity. Full length FlhB purified under solubilizing, nondenaturing conditions formed a stable dimer via its transmembrane domain and stably bound FliH. Together, the present results support the previously hypothesized central role of FlhB and elucidate the dynamics of protein-protein interactions in type III secretion.
File Format	PDF HTM / HTML
DOI	10.1371/journal.pone.0134884
PubMed reference number	26244937
Journal	Medline
Volume Number	10
Alternate Webpage(s)	https://journals.plos.org/plosone/article/file?id=info:doi/10.1371/journal.pone.0134884.s004&type=supplementary
Alternate Webpage(s)	https://digitalcommons.kennesaw.edu/cgi/viewcontent.cgi?article=4406&context=facpubs
Alternate Webpage(s)	http://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0134884&type=printable
Alternate Webpage(s)	https://digitalcommons.kennesaw.edu/cgi/viewcontent.cgi?article=4406&context=facpubs&httpsredir=1&referer=
Alternate Webpage(s)	http://ftp.ncbi.nlm.nih.gov/pub/pmc/69/0f/pone.0134884.PMC4526367.pdf
Alternate Webpage(s)	http://digitalcommons.kennesaw.edu/cgi/viewcontent.cgi?article=4406&context=facpubs
Alternate Webpage(s)	http://digitalcommons.kennesaw.edu/cgi/viewcontent.cgi?article=4555&context=facpubs
Alternate Webpage(s)	https://digitalcommons.kennesaw.edu/cgi/viewcontent.cgi?article=4555&context=facpubs
Journal	PloS one
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article