4FHR

Crystal structure of the complex between the flagellar motor proteins FliG and FliM.

Summary for 4FHR

• Entry DOI: 10.2210/pdb4fhr/pdb
• Related: 1LKV 3AJC 3HJL
• Descriptor: Flagellar motor switch protein FliM, Flagellar motor switch protein FliG (3 entities in total)
• Functional Keywords: flagellar motor, motor protein
• Biological source: Thermotoga maritima; More
• Cellular location: Cell membrane; Peripheral membrane protein; Cytoplasmic side (By similarity): Q9WY63
• Total number of polymer chains: 2
• Total formula weight: 46095.15

Authors

Paz, A.,Vartanian, A.S.,Fortgang, E.A.,Abramson, J.,Dahlquist, F.W. (deposition date: 2012-06-06, release date: 2012-08-22, Last modification date: 2023-09-13)

Primary citation

Vartanian, A.S.,Paz, A.,Fortgang, E.A.,Abramson, J.,Dahlquist, F.W.
Structure of flagellar motor proteins in complex allows for insights into motor structure and switching.
J.Biol.Chem., 287:35779-35783, 2012

PubMed Abstract: The flagellar motor is one type of propulsion device of motile bacteria. The cytoplasmic ring (C-ring) of the motor interacts with the stator to generate torque in clockwise and counterclockwise directions. The C-ring is composed of three proteins, FliM, FliN, and FliG. Together they form the "switch complex" and regulate switching and torque generation. Here we report the crystal structure of the middle domain of FliM in complex with the middle and C-terminal domains of FliG that shows the interaction surface and orientations of the proteins. In the complex, FliG assumes a compact conformation in which the middle and C-terminal domains (FliG(MC)) collapse and stack together similarly to the recently published structure of a mutant of FliG(MC) with a clockwise rotational bias. This intramolecular stacking of the domains is distinct from the intermolecular stacking seen in other structures of FliG. We fit the complex structure into the three-dimensional reconstructions of the motor and propose that the cytoplasmic ring is assembled from 34 FliG and FliM molecules in a 1:1 fashion.

PubMed: 22896702
DOI: 10.1074/jbc.C112.378380

Experimental method

X-RAY DIFFRACTION (1.931 Å)