7SPD

Crystal Structure of The Tetramerization Domain (29-147) From Human Voltage-gated Potassium Channel Kv2.1 in C 2 2 21 Space Group

Summary for 7SPD

• Entry DOI: 10.2210/pdb7spd/pdb
• Descriptor: Potassium voltage-gated channel subfamily B member 1, DI(HYDROXYETHYL)ETHER, ZINC ION, ... (4 entities in total)
• Functional Keywords: pentamer, potassium voltage-gated channel, t1 domain, signaling protein
• Biological source: Homo sapiens (Human)
• Total number of polymer chains: 5
• Total formula weight: 74281.64

Authors

Xu, Z.,Schnicker, N.,Baker, S. (deposition date: 2021-11-02, release date: 2022-06-08, Last modification date: 2023-10-18)

Primary citation

Xu, Z.,Khan, S.,Schnicker, N.J.,Baker, S.
Pentameric assembly of the Kv2.1 tetramerization domain.
Acta Crystallogr D Struct Biol, 78:792-802, 2022

PubMed Abstract: The Kv family of voltage-gated potassium channels regulate neuronal excitability. The biophysical characteristics of Kv channels can be matched to the needs of different neurons by forming homotetrameric or heterotetrameric channels within one of four subfamilies. The cytoplasmic tetramerization (T1) domain plays a major role in dictating the compatibility of different Kv subunits. The only Kv subfamily lacking a representative structure of the T1 domain is the Kv2 family. Here, X-ray crystallography was used to solve the structure of the human Kv2.1 T1 domain. The structure is similar to those of other T1 domains, but surprisingly formed a pentamer instead of a tetramer. In solution the Kv2.1 T1 domain also formed a pentamer, as determined by inline SEC-MALS-SAXS and negative-stain electron microscopy. The Kv2.1 T1-T1 interface involves electrostatic interactions, including a salt bridge formed by the negative charges in a previously described CDD motif, and inter-subunit coordination of zinc. It is shown that zinc binding is important for stability. In conclusion, the Kv2.1 T1 domain behaves differently from the other Kv T1 domains, which may reflect the versatility of Kv2.1, which can assemble with the regulatory KvS subunits and scaffold ER-plasma membrane contacts.

PubMed: 35647925
DOI: 10.1107/S205979832200568X

Experimental method

X-RAY DIFFRACTION (2.7 Å)