5CBF

Structural and Functional Characterization of a Calcium-activated Cation channel from Tsukamurella Paurometabola

Summary for 5CBF

• Entry DOI: 10.2210/pdb5cbf/pdb
• Related: 5CBG 5CBH
• Descriptor: Ion transport 2 domain protein, CALCIUM ION (2 entities in total)
• Functional Keywords: membrane protein, calcium activated non-selective ion channel, 2tm helix ion channel family, tetrameric cation channel, ion transport, transport protein
• Biological source: Tsukamurella paurometabola (strain ATCC 8368 / DSM 20162 / JCM 10117 / NBRC 16120 / NCTC 13040)
• Total number of polymer chains: 6
• Total formula weight: 84830.78

Authors

Dhakshnamoorthy, B.,Rohaim, A.,Rui, H.,Blachowicz, L.,Roux, B. (deposition date: 2015-06-30, release date: 2016-07-20, Last modification date: 2023-09-27)

Primary citation

Dhakshnamoorthy, B.,Rohaim, A.,Rui, H.,Blachowicz, L.,Roux, B.
Structural and functional characterization of a calcium-activated cation channel from Tsukamurella paurometabola.
Nat Commun, 7:12753-12753, 2016

PubMed Abstract: The selectivity filter is an essential functional element of K channels that is highly conserved both in terms of its primary sequence and its three-dimensional structure. Here, we investigate the properties of an ion channel from the Gram-positive bacterium Tsukamurella paurometabola with a selectivity filter formed by an uncommon proline-rich sequence. Electrophysiological recordings show that it is a non-selective cation channel and that its activity depends on Ca concentration. In the crystal structure, the selectivity filter adopts a novel conformation with Ca ions bound within the filter near the pore helix where they are coordinated by backbone oxygen atoms, a recurrent motif found in multiple proteins. The binding of Ca ion in the selectivity filter controls the widening of the pore as shown in crystal structures and in molecular dynamics simulations. The structural, functional and computational data provide a characterization of this calcium-gated cationic channel.

PubMed: 27678077
DOI: 10.1038/ncomms12753

Experimental method

X-RAY DIFFRACTION (3.61 Å)