Expression, purification, crystallization and preliminary crystallographic study of the carboxyl-terminal domain of the human voltage-gated proton channel Hv1

The voltage-gated proton channel Hv1 is essential to proton permeation and contains a voltage-sensor domain without a pore domain. It contains three predicted domains: an N-terminal acid and proline-rich domain, a transmembrane voltage-sensor domain and a C-terminal domain that is responsible for the dimeric architecture of Hv1. Here, the C-terminal domain of the human voltage-gated proton channel Hv1 (C-Hv1) was overexpressed in Escherichia coli, purified and crystallized using the hanging-drop vapour-diffusion method. The crystals have a tetragonal form and diffraction data were collected to 2.5 Å resolution in-house. The crystal belongs to space group P4₁2₁2, with unit-cell parameters a = b = 37.76, c = 137.52 Å. Structural determination of C-Hv1 is in progress.