1t1d

From Proteopedia

Revision as of 23:20, 24 November 2007

CRYSTAL STRUCTURE OF THE TETRAMERIZATION DOMAIN OF THE SHAKER POTASSIUM CHANNEL

Overview

The N-terminal, cytoplasmic tetramerization domain (T1) of voltage-gated, K+ channels encodes molecular determinants for subfamily-specific assembly, of alpha-subunits into functional tetrameric channels. Crystal structures, of T1 tetramers from Shaw and Shaker subfamilies reveal a common, four-layered scaffolding. Within layer 4, on the hypothetical, membrane-facing side of the tetramer, the Shaw T1 tetramer contains four, zinc ions; each is coordinated by a histidine and two cysteines from one, monomer and by one cysteine from an adjacent monomer. The amino acids, involved in coordinating the Zn2+ ion occur in a HX5CX20CC sequence motif, that is highly conserved among all Shab, Shaw and Shal subfamily members, but is not found in Shaker subfamily members. We demonstrate by, coimmunoprecipitation that a few characteristic residues in the subunit, interface are crucial for subfamily-specific tetramerization of the T1, domains.

About this Structure

1T1D is a Single protein structure of sequence from Aplysia californica. Full crystallographic information is available from OCA.

Reference

Zn2+-binding and molecular determinants of tetramerization in voltage-gated K+ channels., Bixby KA, Nanao MH, Shen NV, Kreusch A, Bellamy H, Pfaffinger PJ, Choe S, Nat Struct Biol. 1999 Jan;6(1):38-43. PMID:9886290

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