4JTA

Crystal structure of Kv1.2-2.1 paddle chimera channel in complex with Charybdotoxin

Summary for 4JTA

• Entry DOI: 10.2210/pdb4jta/pdb
• Related: 2CRD 2R9R 4JTC 4JTD
• Descriptor: Voltage-gated potassium channel subunit beta-2, Potassium voltage-gated channel subfamily A member 2, Potassium voltage-gated channel subfamily B member 1, Potassium channel toxin alpha-KTx 1.1, ... (7 entities in total)
• Functional Keywords: potassium channel, pore blocking toxin, protein-protein complex, transport protein-toxin complex, transport protein/toxin
• Biological source: Rattus norvegicus (brown rat,rat,rats); More
• Total number of polymer chains: 5
• Total formula weight: 211114.03

Authors

MacKinnon, R.,Banerjee, A.,Lee, A.,Campbell, E. (deposition date: 2013-03-23, release date: 2013-06-12, Last modification date: 2019-12-25)

Primary citation

Banerjee, A.,Lee, A.,Campbell, E.,Mackinnon, R.
Structure of a pore-blocking toxin in complex with a eukaryotic voltage-dependent K(+) channel.
Elife, 2:e00594-e00594, 2013

PubMed Abstract: Pore-blocking toxins inhibit voltage-dependent K(+) channels (Kv channels) by plugging the ion-conduction pathway. We have solved the crystal structure of paddle chimera, a Kv channel in complex with charybdotoxin (CTX), a pore-blocking toxin. The toxin binds to the extracellular pore entryway without producing discernable alteration of the selectivity filter structure and is oriented to project its Lys27 into the pore. The most extracellular K(+) binding site (S1) is devoid of K(+) electron-density when wild-type CTX is bound, but K(+) density is present to some extent in a Lys27Met mutant. In crystals with Cs(+) replacing K(+), S1 electron-density is present even in the presence of Lys27, a finding compatible with the differential effects of Cs(+) vs K(+) on CTX affinity for the channel. Together, these results show that CTX binds to a K(+) channel in a lock and key manner and interacts directly with conducting ions inside the selectivity filter. DOI:http://dx.doi.org/10.7554/eLife.00594.001.

PubMed: 23705070
DOI: 10.7554/eLife.00594

Experimental method

X-RAY DIFFRACTION (2.5 Å)