Potassium channel Kv1.2 (with beta2 auxiliary subunits), structure in a membrane-like environment. Calculated hydrocarbon boundaries of the
lipid bilayer are indicated by red and blue dots.
They are described as minimally having two
transmembrane helices flanking a loop which determines the
ion selectivity of the channel pore. Many eukaryotic channels have four additional transmembrane helices (TM) (
PfamPF00520), related to or
vestigial of
voltage gating. The proteins with only two transmembrane helices (
PfamPF07885) are most commonly found in bacteria. This also includes the 2-TM
inward-rectifier potassium channels (
PfamPF01007) found primarily in eukaryotes. There are commonly additional regulatory domains which serve to regulate ion conduction and channel gating. The pores may also be
homotetramers or
heterotetramers; where heterotetramers may be encoded as distinct genes or as multiple pore domains within a single polypeptide. The
HVCN1 and
Putative tyrosine-protein phosphatase proteins do not contain an expected ion conduction pore domain, but rather have homology only to the voltage sensor domain of
voltage gated ion channels.
"Voltage-gated Ion Channels". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology. Archived from
the original on 2021-04-17. Retrieved 2008-12-16.
Potassium channel Kv1.2 (with beta2 auxiliary subunits), structure in a membrane-like environment. Calculated hydrocarbon boundaries of the
lipid bilayer are indicated by red and blue dots.
They are described as minimally having two
transmembrane helices flanking a loop which determines the
ion selectivity of the channel pore. Many eukaryotic channels have four additional transmembrane helices (TM) (
PfamPF00520), related to or
vestigial of
voltage gating. The proteins with only two transmembrane helices (
PfamPF07885) are most commonly found in bacteria. This also includes the 2-TM
inward-rectifier potassium channels (
PfamPF01007) found primarily in eukaryotes. There are commonly additional regulatory domains which serve to regulate ion conduction and channel gating. The pores may also be
homotetramers or
heterotetramers; where heterotetramers may be encoded as distinct genes or as multiple pore domains within a single polypeptide. The
HVCN1 and
Putative tyrosine-protein phosphatase proteins do not contain an expected ion conduction pore domain, but rather have homology only to the voltage sensor domain of
voltage gated ion channels.
"Voltage-gated Ion Channels". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology. Archived from
the original on 2021-04-17. Retrieved 2008-12-16.