PDBsum entry 1u12

Membrane protein

PDB id: 1u12

Contents

Protein chains

131 a.a. *

Ligands

SO4 ×2

Metals

__K ×4

IOD ×31

Waters ×11

* Residue conservation analysis

PDB id:

1u12

Name:

Membrane protein

Title:

M. Loti cyclic nucleotide binding domain mutant

Structure:

Cyclic nucleotide binding domain. Chain: a, b. Fragment: cyclic nucleotide binding domain, cytoplasmic domain. Engineered: yes. Mutation: yes

Source:

Mesorhizobium loti. Organism_taxid: 266835. Strain: maff303099. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.70Å R-factor: 0.253 R-free: 0.281

Authors:

G.M.Clayton,W.R.Silverman,L.Heginbotham,J.H.Morais-Cabral

Key ref:

G.M.Clayton et al. (2004). Structural basis of ligand activation in a cyclic nucleotide regulated potassium channel. Cell, 119, 615-627. PubMed id: 15550244 DOI: 10.1016/j.cell.2004.10.030

Date:

14-Jul-04 Release date: 30-Nov-04

Protein chains

Q98GN8  (CNGK1_RHILO) -  Cyclic nucleotide-gated potassium channel mll3241 from Mesorhizobium japonicum (strain LMG 29417 / CECT 9101 / MAFF 303099)

Seq: 355 a.a.

Struc: 131 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

DOI no: 10.1016/j.cell.2004.10.030

Cell 119:615-627 (2004)

PubMed id: 15550244

Structural basis of ligand activation in a cyclic nucleotide regulated potassium channel.

G.M.Clayton, W.R.Silverman, L.Heginbotham, J.H.Morais-Cabral.

ABSTRACT

Here we describe the initial functional characterization of a cyclic nucleotide regulated ion channel from the bacterium Mesorhizobium loti and present two structures of its cyclic nucleotide binding domain, with and without cAMP. The domains are organized as dimers with the interface formed by the linker regions that connect the nucleotide binding pocket to the pore domain. Together, structural and functional data suggest the domains form two dimers on the cytoplasmic face of the channel. We propose a model for gating in which ligand binding alters the structural relationship within a dimer, directly affecting the position of the adjacent transmembrane helices.

Selected figure(s)

Figure 5.
Figure 5. Dimer Interface(A) Ribbon representation of the R348A mutant dimer, with ions bound in the ligand binding sites. Side chains of some residues on the interface are shown.(B) Stereoviews of the dimer interface from the wild-type (top) and mutant (bottom) domain structures. The αC of Gly221 is shown as a purple sphere. TM, transmembrane helix.

Figure 7.
Figure 7. Schematic of Gating ModelTwo of the four CNB domains are shown attached to the last transmembrane helices. The open and closed states correspond to liganded and unliganded structures, respectively. Arrows indicate the direction of movement to attain the structure shown, from the alternate conformation. The orientation of the domains relative to the transmembrane helices is arbitrary.

The above figures are reprinted by permission from Cell Press: Cell (2004, 119, 615-627) copyright 2004.

Figures were selected by an automated process.