Structural flexibility of the periplasmic protein, FlgA, regulates flagellar P-ring assembly in Salmonella enterica.
A periplasmic flagellar chaperone protein, FlgA, is required for P-ring assembly in bacterial flagella of taxa such as Salmonella enterica or Escherichia coli. The mechanism of chaperone-mediated P-ring formation is poorly understood. Here we present the open and closed crystal structures of FlgA from Salmonella enterica serovar Typhimurium, grown under different crystallization conditions. An intramolecular disulfide cross-linked form of FlgA caused a dominant negative effect on motility of the wild-type strain. Pull-down experiments support a specific protein-protein interaction between FlgI, the P-ring component protein, and the C-terminal domain of FlgA. Surface plasmon resonance and limited-proteolysis indicate that flexibility of the domain is reduced in the covalently closed form. These results show that the structural flexibility of the C-terminal domain of FlgA, which is related to the structural difference between the two crystal forms, is intrinsically associated with its molecular chaperone function in P-ring assembly.
Trans-Membrane Trafficking Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna, Kunigami, Okinawa 904-0495, Japan.
Hideyuki
H
Matsunami
Trans-Membrane Trafficking Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna, Kunigami, Okinawa 904-0495, Japan.
Young-Ho
YH
Yoon
Trans-Membrane Trafficking Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna, Kunigami, Okinawa 904-0495, Japan.
Vladimir A
VA
Meshcheryakov
Dynamic NanoM achine Project, International Cooperative Research Project, Japan Science and Technology Agency, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan.|Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan.|Riken Quantitative Biology Center, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan.
Keiichi
K
Namba
Trans-Membrane Trafficking Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna, Kunigami, Okinawa 904-0495, Japan.
Fadel A
FA
Samatey
D021301:Antifreeze Proteins / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D019897:Periplasm / Q000378:metabolism*; D011487:Protein Conformation; D019779:Salmonella enterica / Q000378:metabolism*
D021301:Antifreeze Proteins; D001426:Bacterial Proteins; C087497:FlgA protein, Salmonella