PDBsum entry 1id1

Membrane protein

PDB id: 1id1

Contents

Protein chains

153 a.a. *

Waters ×57

* Residue conservation analysis

PDB id:

1id1

Name:

Membrane protein

Title:

Crystal structure of the rck domain from e.Coli potassium channel

Structure:

Putative potassium channel protein. Chain: a, b. Fragment: c-terminal domain, residues 241-393. Engineered: yes

Source:

Escherichia coli. Organism_taxid: 562. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

Biol. unit:

Dimer (from PQS)

Resolution:

2.40Å R-factor: 0.208 R-free: 0.236

Authors:

Y.Jiang,A.Pico,M.Cadene,B.T.Chait,R.Mackinnon

Key ref:

Y.Jiang et al. (2001). Structure of the RCK domain from the E. coli K+ channel and demonstration of its presence in the human BK channel. Neuron, 29, 593-601. PubMed id: 11301020 DOI: 10.1016/S0896-6273(01)00236-7

Date:

02-Apr-01 Release date: 11-Apr-01

Protein chains

P31069  (KCH_ECOLI) -  Voltage-gated potassium channel Kch from Escherichia coli (strain K12)

Seq: 417 a.a.

Struc: 153 a.a.

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1016/S0896-6273(01)00236-7

Neuron 29:593-601 (2001)

PubMed id: 11301020

Structure of the RCK domain from the E. coli K+ channel and demonstration of its presence in the human BK channel.

Y.Jiang, A.Pico, M.Cadene, B.T.Chait, R.MacKinnon.

ABSTRACT

The intracellular C-terminal domain structure of a six-transmembrane K+ channel from Escherichia coli has been solved by X-ray crystallography at 2.4 A resolution. The structure is representative of a broad class of domains/proteins that regulate the conductance of K+ (here referred to as RCK domains) in prokaryotic K+ transporters and K+ channels. The RCK domain has a Rossmann-fold topology with unique positions, not commonly conserved among Rossmann-fold proteins, composing a well-conserved salt bridge and a hydrophobic dimer interface. Structure-based amino acid sequence alignments and mutational analysis are used to demonstrate that an RCK domain is also present and is an important component of the gating machinery in eukaryotic large-conductance Ca2+ activated K+ channels.

Selected figure(s)

Figure 1.
Figure 1. A Visual Argument for Channel Regulation by C-Terminal Cytoplasmic Domains(A) Depiction of the aperture formed by inner helices (red) of the tetrameric KcsA K^+ channel with a nondescript C-terminal domain (gray).(B) Example topologies of varied subfamilies of K^+ channels: (i) prokaryotic K^+ channels with two transmembrane (TM) helices and a putative NAD binding RCK domain (shaded); (ii) prokaryotic K^+ channels with six TM helices and an RCK domain (e.g., E. coli Kch); (iii) eukaryotic large-conductance Ca^2+-activated K^+ channels (BK) with a homologous RCK domain and C-terminal Ca^2+ binding domain; (iv) eukaryotic small-conductance Ca^2+-activated K^+ channels (SK) with a calmodulin binding domain; (v) eukaryotic cyclic nucleotide–gated channels (CNG) with a cNMP binding domain; and (vi) eukaryotic ATP-sensitive inward rectifier K^+ channels (Kir6.1 and 6.2) with an ATP binding domain

Figure 4.
Figure 4. Comparison between the E. coli K^+ Channel RCK Domain Dimer and the E. coli LIV Binding Protein(A) Stereo view of the Cα trace of the E. coli K^+ channel RCK domain dimer. Subunits are black and red.(B) Stereo view of the Cα trace of the E. coli LIV binding protein

The above figures are reprinted by permission from Cell Press: Neuron (2001, 29, 593-601) copyright 2001.

Figures were selected by an automated process.