6DZ1

Studies of Ion Transport in K+ Channels

Summary for 6DZ1

• Entry DOI: 10.2210/pdb6dz1/pdb
• Descriptor: Potassium channel protein, POTASSIUM ION, (4S)-2-METHYL-2,4-PENTANEDIOL, ... (4 entities in total)
• Functional Keywords: k ion transport channel, membrane protein
• Biological source: Bacillus cereus BDRD-Cer4
• Total number of polymer chains: 2
• Total formula weight: 21884.30

Authors

Langan, P.S.,Vandavasi, V.G.,Weiss, K.L.,Wagner, A.,Duman, R.,El Omari, K.,Afonine, P.V.,Coates, L. (deposition date: 2018-07-02, release date: 2018-11-14, Last modification date: 2024-03-13)

Primary citation

Langan, P.S.,Vandavasi, V.G.,Weiss, K.L.,Afonine, P.V.,El Omari, K.,Duman, R.,Wagner, A.,Coates, L.
Anomalous X-ray diffraction studies of ion transport in K+channels.
Nat Commun, 9:4540-4540, 2018

PubMed Abstract: Potassium ion channels utilize a highly selective filter to rapidly transport K ions across cellular membranes. This selectivity filter is composed of four binding sites which display almost equal electron density in crystal structures with high potassium ion concentrations. This electron density can be interpreted to reflect a superposition of alternating potassium ion and water occupied states or as adjacent potassium ions. Here, we use single wavelength anomalous dispersion (SAD) X-ray diffraction data collected near the potassium absorption edge to show experimentally that all ion binding sites within the selectivity filter are fully occupied by K ions. These data support the hypothesis that potassium ion transport occurs by direct Coulomb knock-on, and provide an example of solving the phase problem by K-SAD.

PubMed: 30382100
DOI: 10.1038/s41467-018-06957-w

Experimental method

X-RAY DIFFRACTION (2.26 Å)