First time at Proteopedia? Click on the green links, they change the 3D image. Click and drag the molecules. Proteopedia is a 3D, interactive encyclopedia of proteins, RNA, DNA and other molecules. With a free user account, you can edit pages in Proteopedia. Visit the Main Page to learn more.
1f6g
From Proteopedia
| 1f6g, 8 NMR models () | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Related: | 1bl8 | ||||||||
| |||||||||
| |||||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||
POTASSIUM CHANNEL (KCSA) FULL-LENGTH FOLD
The molecular architecture of the NH(2) and COOH termini of the prokaryotic potassium channel KcsA has been determined using site-directed spin-labeling methods and paramagnetic resonance EPR spectroscopy. Cysteine mutants were generated (residues 5-24 and 121-160) and spin labeled, and the X-band CW EPR spectra were obtained from liposome-reconstituted channels at room temperature. Data on probe mobility (DeltaHo(-1)), accessibility parameters (PiO(2) and PiNiEdda), and inter-subunit spin-spin interaction (Omega) were used as structural constraints to build a three-dimensional folding model of these cytoplasmic domains from a set of simulated annealing and restrained molecular dynamics runs. 32 backbone structures were generated and averaged using fourfold symmetry, and a final mean structure was obtained from the eight lowest energy runs. Based on the present data, together with information from the KcsA crystal structure, a model for the three-dimensional fold of full-length KcsA was constructed. In this model, the NH(2) terminus of KcsA forms an alpha-helix anchored at the membrane-water interface, while the COOH terminus forms a right-handed four-helix bundle that extend some 40-50 A towards the cytoplasm. Functional analysis of COOH-terminal deletion constructs suggest that, while the COOH terminus does not play a substantial role in determining ion permeation properties, it exerts a modulatory role in the pH-dependent gating mechanism.
Molecular architecture of full-length KcsA: role of cytoplasmic domains in ion permeation and activation gating., Cortes DM, Cuello LG, Perozo E, J Gen Physiol. 2001 Feb;117(2):165-80. PMID:11158168
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
About this Structure
1F6G is a 4 chains structure with sequences from Streptomyces lividans. The February 2003 RCSB PDB Molecule of the Month feature on Potassium Channels by Shuchismita Dutta and David S. Goodsell is 10.2210/rcsb_pdb/mom_2003_2. Full experimental information is available from OCA.
Reference
- Cortes DM, Cuello LG, Perozo E. Molecular architecture of full-length KcsA: role of cytoplasmic domains in ion permeation and activation gating. J Gen Physiol. 2001 Feb;117(2):165-80. PMID:11158168
Page seeded by OCA on Thu Jan 21 09:08:00 2010
