7CTN

Structure of the 328-692 fragment of FlhA (E351A/D356A)

Summary for 7CTN

• Entry DOI: 10.2210/pdb7ctn/pdb
• Related: 3A5I 6AI0
• Descriptor: Flagellar biosynthesis protein FlhA (1 entity in total)
• Functional Keywords: flagellar type iii secretion, protein transport
• Biological source: Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)
• Total number of polymer chains: 2
• Total formula weight: 81317.38

Authors

Kida, M.,Takekawa, N.,Kinoshita, M.,Inoue, Y.,Minamino, T.,Imada, K. (deposition date: 2020-08-19, release date: 2021-04-28, Last modification date: 2023-11-29)

Primary citation

Inoue, Y.,Kinoshita, M.,Kida, M.,Takekawa, N.,Namba, K.,Imada, K.,Minamino, T.
The FlhA linker mediates flagellar protein export switching during flagellar assembly.
Commun Biol, 4:646-646, 2021

PubMed Abstract: The flagellar protein export apparatus switches substrate specificity from hook-type to filament-type upon hook assembly completion, thereby initiating filament assembly at the hook tip. The C-terminal cytoplasmic domain of FlhA (FlhA) serves as a docking platform for flagellar chaperones in complex with their cognate filament-type substrates. Interactions of the flexible linker of FlhA (FlhA) with its nearest FlhA subunit in the FlhA ring is required for the substrate specificity switching. To address how FlhA brings the order to flagellar assembly, we analyzed the flhA(E351A/W354A/D356A) ΔflgM mutant and found that this triple mutation in FlhA increased the secretion level of hook protein by 5-fold, thereby increasing hook length. The crystal structure of FlhA(E351A/D356A) showed that FlhA bound to the chaperone-binding site of its neighboring subunit. We propose that the interaction of FlhA with the chaperon-binding site of FlhA suppresses filament-type protein export and facilitates hook-type protein export during hook assembly.

PubMed: 34059784
DOI: 10.1038/s42003-021-02177-z

Experimental method

X-RAY DIFFRACTION (2.8 Å)