PDBsum entry 3lut

Membrane protein

PDB id: 3lut

Contents

Protein chains

326 a.a. *

390 a.a. *

Ligands

NAP

Metals

__K ×6

Waters ×86

* Residue conservation analysis

PDB id:

3lut

Name:

Membrane protein

Title:

A structural model for the full-length shaker potassium channel kv1.2

Structure:

Voltage-gated potassium channel subunit beta-2. Chain: a. Synonym: k(+) channel subunit beta-2, kv-beta-2. Engineered: yes. Potassium voltage-gated channel subfamily a member 2. Chain: b. Synonym: voltage-gated potassium channel subunit kv1.2, rbk2, rck5, rak. Engineered: yes.

Source:

Rattus norvegicus. Rat. Organism_taxid: 10116. Gene: kcnab2, ckbeta2, kcnb3. Expressed in: pichia pastoris. Expression_system_taxid: 4922. Gene: kcna2. Expression_system_taxid: 4922

Resolution:

2.90Å R-factor: 0.212 R-free: 0.221

Authors:

X.Chen,F.Ni,Q.Wang,J.Ma

Key ref:

X.Chen et al. (2010). Structure of the full-length Shaker potassium channel Kv1.2 by normal-mode-based X-ray crystallographic refinement. Proc Natl Acad Sci U S A, 107, 11352-11357. PubMed id: 20534430

Date:

18-Feb-10 Release date: 23-Jun-10

Protein chain

P62483  (KCAB2_RAT) -  Voltage-gated potassium channel subunit beta-2 from Rattus norvegicus

Seq: 367 a.a.

Struc: 326 a.a.

Protein chain

P63142  (KCNA2_RAT) -  Potassium voltage-gated channel subfamily A member 2 from Rattus norvegicus

Seq: 499 a.a.

Struc: 390 a.a.*

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

Enzyme reactions

• Enzyme class 1: Chain A: E.C.1.1.1.- - ?????
• Enzyme class 2: Chain B: E.C.?

Note, where more than one E.C. class is given (as above), each may correspond to a different protein domain or, in the case of polyprotein precursors, to a different mature protein.

Proc Natl Acad Sci U S A 107:11352-11357 (2010)

PubMed id: 20534430

Structure of the full-length Shaker potassium channel Kv1.2 by normal-mode-based X-ray crystallographic refinement.

X.Chen, Q.Wang, F.Ni, J.Ma.

ABSTRACT

Voltage-dependent potassium channels (Kv) are homotetramers composed of four voltage sensors and one pore domain. Because of high-level structural flexibility, the first mammalian Kv structure, Kv1.2 at 2.9 A, has about 37% molecular mass of the transmembrane portion not resolved. In this study, by applying a novel normal-mode-based X-ray crystallographic refinement method to the original diffraction data and structural model, we established the structure of full-length Kv1.2 in its native form. This structure offers mechanistic insights into voltage sensing. Particularly, it shows a hydrophobic layer of about 10 A at the midpoint of the membrane bilayer, which is likely the molecular basis for the observed "focused electric field" of Kv1.2 between the internal and external solutions. This work also demonstrated the potential of the refinement method in bringing up large chunks of missing densities, thus beneficial to structural refinement of many difficult systems.