Details

Autor(en) / Beteiligte

• Goldstein, Steve A. N
• Tai, Kwok-Keung

Titel

The conduction pore of a cardiac potassium channel

Ist Teil von

• Nature (London), 1998-02, Vol.391 (6667), p.605-608

Ort / Verlag

London: Nature Publishing

Erscheinungsjahr

1998

Link zum Volltext

Quelle

PBSC : Psychology and Behavioral Sciences Collection - Journals

Beschreibungen/Notizen

• Ion channels form transmembrane water-filled pores that allow ions to cross membranes in a rapid and selective fashion. The amino acid residues that line these pores have been sought to reveal the mechanisms of ion conduction and selectivity. The pore (P) loop is a stretch of residues that influences single-channel-current amplitude, selectivity among ions and open-channel blockade,, and is conserved in potassium-channel subunits previously recognized to contribute to pore formation,. To date, potassium-channel pores have been shown to form by symmetrical alignment of four P loops around a central conduction pathway. Here we show that the selectivity-determining pore region of the voltage-gated potassium channel of human heart through which the IKs current passes includes the transmembrane segment of the non-P-loop protein minK. Two adjacent residues in this segment of minK are exposed in the pore on either side of a short barrier that restricts the movement of sodium, cadmium and zinc ions across the membrane. Thus, potassium-selective pores are not restricted to P loops or a strict P-loop geometry.