PDBsum entry 6ufe

Membrane protein

PDB id: 6ufe

Contents

Protein chains

90 a.a.

Ligands

MPD ×10

Metals

__K ×8

Waters ×83

PDB id:

6ufe

Name:

Membrane protein

Title:

The structure of a potassium selective ion channel at atomic resolution

Structure:

Transporter. Chain: a, b. Synonym: voltage-gated potassium channel. Engineered: yes. Mutation: yes

Source:

Bacillus cereus. Organism_taxid: 1396. Gene: a9485_19160, bacere00184_02078, cj306_03585, cn950_06075, cn980_22870, coi98_17615, con37_12595. Expressed in: escherichia coli. Expression_system_taxid: 562

Resolution:

1.20Å R-factor: 0.133 R-free: 0.148

Authors:

P.S.Langan,V.G.Vandavasi,B.Sullivan,P.V.Afonine,K.L.Weiss

Key ref:

P.S.Langan et al. (2020). The structure of a potassium-selective ion channel reveals a hydrophobic gate regulating ion permeation. IUCrJ, 7, 835-843. PubMed id: 32939275 DOI: 10.1107/S2052252520008271

Date:

24-Sep-19 Release date: 05-Aug-20

Protein chains

Q81HW2  (Q81HW2_BACCR) -  Potassium channel protein from Bacillus cereus (strain ATCC 14579 / DSM 31 / CCUG 7414 / JCM 2152 / NBRC 15305 / NCIMB 9373 / NCTC 2599 / NRRL B-3711)

Seq: 114 a.a.

Struc: 90 a.a.*

* PDB and UniProt seqs differ at 4 residue positions (black crosses)

DOI no: 10.1107/S2052252520008271

IUCrJ 7:835-843 (2020)

PubMed id: 32939275

The structure of a potassium-selective ion channel reveals a hydrophobic gate regulating ion permeation.

P.S.Langan, V.G.Vandavasi, W.Kopec, B.Sullivan, P.V.Afonne, K.L.Weiss, B.L.de Groot, L.Coates.

ABSTRACT

Protein dynamics are essential to function. One example of this is the various gating mechanisms within ion channels, which are transmembrane proteins that act as gateways into the cell. Typical ion channels switch between an open and closed state via a conformational transition which is often triggered by an external stimulus, such as ligand binding or pH and voltage differences. The atomic resolution structure of a potassium-selective ion channel named NaK2K has allowed us to observe that a hydro-phobic residue at the bottom of the selectivity filter, Phe92, appears in dual conformations. One of the two conformations of Phe92 restricts the diameter of the exit pore around the selectivity filter, limiting ion flow through the channel, while the other conformation of Phe92 provides a larger-diameter exit pore from the selectivity filter. Thus, it can be concluded that Phe92 acts as a hydro-phobic gate, regulating the flow of ions through the selectivity filter.