4MQX

CLC-ec1 Fab Complex Cysless A399C-A432C mutant

Summary for 4MQX

• Entry DOI: 10.2210/pdb4mqx/pdb
• Related: 1OTS
• Descriptor: H(+)/Cl(-) exchange transporter ClcA, ecCLC, ERIC, ... (4 entities in total)
• Functional Keywords: alpha helical transmembrane protein, cl/h antiporter, metal transport, membrane protein
• Biological source: Escherichia coli; More
• Cellular location: Cell inner membrane; Multi-pass membrane protein (Probable): P37019
• Total number of polymer chains: 6
• Total formula weight: 193250.02

Authors

Basilio, D.,Noack, K.,Picollo, A.,Accardi, A. (deposition date: 2013-09-16, release date: 2014-04-16, Last modification date: 2024-11-27)

Primary citation

Basilio, D.,Noack, K.,Picollo, A.,Accardi, A.
Conformational changes required for H(+)/Cl(-) exchange mediated by a CLC transporter.
Nat.Struct.Mol.Biol., 21:456-463, 2014

PubMed Abstract: CLC-type exchangers mediate transmembrane Cl(-) transport. Mutations altering their gating properties cause numerous genetic disorders. However, their transport mechanism remains poorly understood. In conventional models, two gates alternatively expose substrates to the intra- or extracellular solutions. A glutamate was identified as the only gate in the CLCs, suggesting that CLCs function by a nonconventional mechanism. Here we show that transport in CLC-ec1, a prokaryotic homolog, is inhibited by cross-links constraining movement of helix O far from the transport pathway. Cross-linked CLC-ec1 adopts a wild-type-like structure, indicating stabilization of a native conformation. Movements of helix O are transduced to the ion pathway via a direct contact between its C terminus and a tyrosine that is a constitutive element of the second gate of CLC transporters. Therefore, the CLC exchangers have two gates that are coupled through conformational rearrangements outside the ion pathway.

PubMed: 24747941
DOI: 10.1038/nsmb.2814

Experimental method

X-RAY DIFFRACTION (3.516 Å)