 |
PDBsum entry 1qdw
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Signaling protein
|
PDB id
|
|
|
|
1qdw
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
Contents |
 |
|
|
|
|
|
|
|
|
|
|
* Residue conservation analysis
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
The polar t1 interface is linked to conformational changes that open the voltage-Gated potassium channel.
|
|
|
Authors
|
|
D.L.Minor,
Y.F.Lin,
B.C.Mobley,
A.Avelar,
Y.N.Jan,
L.Y.Jan,
J.M.Berger.
|
|
|
Ref.
|
|
Cell, 2000,
102,
657-670.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
Kv voltage-gated potassium channels share a cytoplasmic assembly domain, T1.
Recent mutagenesis of two T1 C-terminal loop residues implicates T1 in channel
gating. However, structural alterations of these mutants leave open the question
concerning direct involvement of T1 in gating. We find in mammalian Kv1.2 that
gating depends critically on residues at complementary T1 surfaces in an
unusually polar interface. An isosteric mutation in this interface causes
surprisingly little structural alteration while stabilizing the closed channel
and increasing the stability of T1 tetramers. Replacing T1 with a tetrameric
coiled-coil destabilizes the closed channel. Together, these data suggest that
structural changes involving the buried polar T1 surfaces play a key role in the
conformational changes leading to channel opening.
|
|
|
|
|
|
|
|
Figure 5.
Figure 5. T1 Interface Mutations That Affect Gating Cluster
into “Hot Spots” on the Interface Surface(A) Molecular
surface, cutaway view of the T1 tetramer seen from the side with
one subunit deleted. “Side A” and “side B” of the
interface are indicated. Residues are color-coded according to
their effects on channel gating. Red indicates ΔV[1/2] of ≥
|5 mV|, green indicates no significant change, and purple
indicates residues intolerant to change.(B) and (C), external
views of the T1 tetramer revealing the accessibility of hot spot
residues from the exterior of T1.
|
|
Figure 7.
Figure 7. Cartoon of an Intact Kv ChannelThe 4-fold axis in
T1 is aligned with the 4-fold axis presumed to run through the
channel pore. Transmembrane segments and C-terminal domains are
indicated for two subunits and colored as in Figure 1. The green
hexagon represents the N-terminal inactivation ball present in
some Kv channels. Only one inactivation ball is shown for
clarity.
|
|
|
|
|
|
The above figures are
reprinted
by permission from Cell Press:
Cell
(2000,
102,
657-670)
copyright 2000.
|
|
|
|
|
|
|
