8BMS

Cryo-EM structure of the mutant solitary ECF module 2EQ in MSP2N2 lipid nanodiscs in the ATPase closed and ATP-bound conformation

Summary for 8BMS

• Entry DOI: 10.2210/pdb8bms/pdb
• EMDB information: 16124
• Descriptor: Energy-coupling factor transporter ATP-binding protein EcfA1, Energy-coupling factor transporter ATP-binding protein EcfA2, Energy-coupling factor transporter transmembrane protein EcfT, ... (6 entities in total)
• Functional Keywords: abc transporter, ecf transporter complex, motor, membrane protein
• Biological source: Lactobacillus delbrueckii subsp. bulgaricus ATCC 11842 = JCM 1002; More
• Total number of polymer chains: 3
• Total formula weight: 93825.30

Authors

Thangaratnarajah, C.,Rheinberger, J.,Paulino, C.,Slotboom, D.J. (deposition date: 2022-11-10, release date: 2023-08-02, Last modification date: 2024-07-24)

Primary citation

Thangaratnarajah, C.,Nijland, M.,Borges-Araujo, L.,Jeucken, A.,Rheinberger, J.,Marrink, S.J.,Souza, P.C.T.,Paulino, C.,Slotboom, D.J.
Expulsion mechanism of the substrate-translocating subunit in ECF transporters.
Nat Commun, 14:4484-4484, 2023

PubMed Abstract: Energy-coupling factor (ECF)-type transporters mediate the uptake of micronutrients in many bacteria. They consist of a substrate-translocating subunit (S-component) and an ATP-hydrolysing motor (ECF module) Previous data indicate that the S-component topples within the membrane to alternately expose the binding site to either side of the membrane. In many ECF transporters, the substrate-free S-component can be expelled from the ECF module. Here we study this enigmatic expulsion step by cryogenic electron microscopy and reveal that ATP induces a concave-to-convex shape change of two long helices in the motor, thereby destroying the S-component's docking site and allowing for its dissociation. We show that adaptation of the membrane morphology to the conformational state of the motor may favour expulsion of the substrate-free S-component when ATP is bound and docking of the substrate-loaded S-component after hydrolysis. Our work provides a picture of bilayer-assisted chemo-mechanical coupling in the transport cycle of ECF transporters.

PubMed: 37491368
DOI: 10.1038/s41467-023-40266-1

Experimental method

ELECTRON MICROSCOPY (2.6 Å)