6BQO

Structure of a dual topology fluoride channel with monobody S8

Summary for 6BQO

• Entry DOI: 10.2210/pdb6bqo/pdb
• Descriptor: Fluoride ion transporter CrcB, Monobody S8, FLUORIDE ION, ... (6 entities in total)
• Functional Keywords: fluoride channel, monobody, dual topology, membrane protein
• Biological source: Bordetella pertussis (strain Tohama I / ATCC BAA-589 / NCTC 13251); More
• Total number of polymer chains: 3
• Total formula weight: 38097.34

Authors

Stockbridge, R.B.,Newstead, S.,McIlwain, B.C. (deposition date: 2017-11-28, release date: 2018-03-07, Last modification date: 2023-10-04)

Primary citation

McIlwain, B.C.,Newstead, S.,Stockbridge, R.B.
Cork-in-Bottle Occlusion of Fluoride Ion Channels by Crystallization Chaperones.
Structure, 26:635-639.e1, 2018

PubMed Abstract: Crystallization of dual-topology fluoride (Fluc) channels requires small, soluble crystallization chaperones known as monobodies, which act as primary crystal lattice contacts. Previous structures of Flucs have been solved in the presence of monobodies that inhibit fluoride currents in single-channel electrophysiological recordings. These structures have revealed two-fold symmetric, doubly bound arrangements, with one monobody on each side of the membrane. The combined electrophysiological and structural observations raise the possibility that chaperone binding allosterically closes the channel, altering the structure from its conducting form. To address this, we identify and solve the structure with a different monobody that only partially blocks fluoride currents. The structure of the channel-monobody complex is asymmetric, with monobody bound to one side of the channel only. The channel conformation is nearly identical on the bound and uncomplexed sides, and to all previously solved structures, providing direct structural evidence that monobody binding does not induce local structural changes.

PubMed: 29526432
DOI: 10.1016/j.str.2018.02.004

Experimental method

X-RAY DIFFRACTION (2.8 Å)