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KcsA was the first potassium ion channel to be characterized using x-ray crystallography by Roderick MacKinnon and his colleagues in 1998. In the years leading up to this, research on the structure of K + channels was centered on the use of small toxin binding to reveal the location of the pore and selectivity filter among channel residues.
The structure of the mammalian voltage-gated K + channel has been used to explain its ability to respond to the voltage across the membrane. Upon opening of the channel, conformational changes in the voltage-sensor domains (VSD) result in the transfer of 12-13 elementary charges across the membrane electric field.
The flux of ions through the potassium channel pore is regulated by two related processes, termed gating and inactivation. Gating is the opening or closing of the channel in response to stimuli, while inactivation is the rapid cessation of current from an open potassium channel and the suppression of the channel's ability to resume conducting.
This subunit of the channel is made up of seven trans-membrane units, and a large intracellular region. The voltage sensor is made by the S4 transmembrane region, which has several Arginine residues which act to ‘sense’ the changes in charge and move in a very similar way to other voltage gated potassium channels.
K+ channel tetramerisation domain is the N-terminal, cytoplasmic tetramerisation domain (T1) of voltage-gated K+ channels. It defines molecular determinants for subfamily-specific assembly of alpha-subunits into functional tetrameric channels. It is distantly related to the BTB/POZ domain Pfam PF00651.
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Calcium-activated potassium channel subunit alpha-1 also known as large conductance calcium-activated potassium channel, subfamily M, alpha member 1 (K Ca 1.1), or BK channel alpha subunit, [5] is a voltage gated potassium channel encoded by the KCNMA1 gene and characterized by their large conductance of potassium ions (K+) through cell membranes.
KCNQ genes encode family members of the Kv7 potassium channel family. These include K v 7.1 - KvLQT1, K v 7.2 , K v 7.3 , K v 7.4 , and K v 7.5 . Four of these (KCNQ2-5) are expressed in the nervous system. They constitute a group of low-threshold voltage-gated K + channels originally termed the ‘M-channel’ (see M-current).