PDBsum entry 6feh

Metal transport

PDB id: 6feh

Contents

Protein chains

115 a.a.

148 a.a.

Metals

_CA ×4

PDB id:

6feh

Name:

Metal transport

Title:

Solution structure of cam/kv7.2-hab complex

Structure:

Potassium voltage-gated channel subfamily kqt member 2, potassium voltage-gated channel subfamily kqt member 2. Chain: a. Synonym: kqt-like 2,neuroblastoma-specific potassium channel subunit alpha kvlqt2,voltage-gated potassium channel subunit kv7.2,kqt-like 2,neuroblastoma-specific potassium channel subunit alpha kvlqt2, voltage-gated potassium channel subunit kv7.2. Engineered: yes. Mutation: yes.

Source:

Homo sapiens. Human. Organism_taxid: 9606. Gene: kcnq2. Expressed in: escherichia coli. Expression_system_taxid: 562. Gene: calm1, calm, cam, cam1.

NMR struc:

10 models

Authors:

G.Bernardo-Seisdedos,A.Villarroel,O.Millet

Key ref:

G.Bernardo-Seisdedos et al. (2018). Structural basis and energy landscape for the Ca²⁺gating and calmodulation of the Kv7.2 K⁺channel. Proc Natl Acad Sci U S A, 115, 2395-2400. PubMed id: 29463698

Date:

02-Jan-18 Release date: 21-Feb-18

Protein chain

O43526  (KCNQ2_HUMAN) -  Potassium voltage-gated channel subfamily KQT member 2 from Homo sapiens

Seq: 872 a.a.

Struc: 115 a.a.*

Protein chain

P0DP23  (CALM1_HUMAN) -  Calmodulin-1 from Homo sapiens

Seq: 149 a.a.

Struc: 148 a.a.

* PDB and UniProt seqs differ at 57 residue positions (black crosses)

Proc Natl Acad Sci U S A 115:2395-2400 (2018)

PubMed id: 29463698

Structural basis and energy landscape for the Ca²⁺gating and calmodulation of the Kv7.2 K⁺channel.

G.Bernardo-Seisdedos, E.Nuñez, C.Gomis-Perez, C.Malo, �.�.Villarroel, O.Millet.

ABSTRACT

The Kv7.2 (KCNQ2) channel is the principal molecular component of the slow voltage-gated, noninactivating K⁺M-current, a key controller of neuronal excitability. To investigate the calmodulin (CaM)-mediated Ca²⁺gating of the channel, we used NMR spectroscopy to structurally and dynamically describe the association of heliceshA andhB of Kv7.2 with CaM, as a function of Ca²⁺concentration. The structures of the CaM/Kv7.2-hAB complex at two different calcification states are reported here. In the presence of a basal cytosolic Ca²⁺concentration (10-100 nM), only the N-lobe of CaM is Ca²⁺-loaded and the complex (representative of the open channel) exhibits collective dynamics on the millisecond time scale toward a low-populated excited state (1.5%) that corresponds to the inactive state of the channel. In response to a chemical or electrical signal, intracellular Ca²⁺levels rise up to 1-10 μM, triggering Ca²⁺association with the C-lobe. The associated conformational rearrangement is the key biological signal that shifts populations to the closed/inactive channel. This reorientation affects the C-lobe of CaM and both helices in Kv7.2, allosterically transducing the information from the Ca²⁺-binding site to the transmembrane region of the channel.