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Structure of potassium channels.

Kuang Q, Purhonen P, Hebert H - Cell. Mol. Life Sci. (2015)

Bottom Line: Potassium channels ubiquitously exist in nearly all kingdoms of life and perform diverse but important functions.The general properties shared by all potassium channels are introduced first, followed by specific features in each class.Our purpose is to help readers to grasp the basic concepts, to be familiar with the property of the different domains, and to understand the structure and function of the potassium channels better.

View Article: PubMed Central - PubMed

Affiliation: Department of Biosciences and Nutrition, Karolinska Institutet, Novum, 14183, Huddinge, Sweden. Qie.Kuang@ki.se.

ABSTRACT
Potassium channels ubiquitously exist in nearly all kingdoms of life and perform diverse but important functions. Since the first atomic structure of a prokaryotic potassium channel (KcsA, a channel from Streptomyces lividans) was determined, tremendous progress has been made in understanding the mechanism of potassium channels and channels conducting other ions. In this review, we discuss the structure of various kinds of potassium channels, including the potassium channel with the pore-forming domain only (KcsA), voltage-gated, inwardly rectifying, tandem pore domain, and ligand-gated ones. The general properties shared by all potassium channels are introduced first, followed by specific features in each class. Our purpose is to help readers to grasp the basic concepts, to be familiar with the property of the different domains, and to understand the structure and function of the potassium channels better.

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Activated, inactivated, and flipped SF structures of KcsA, viewed along the membrane plane. a Comparison of conductive (PDB: 1K4C, black) and nonconductive (PDB: 1K4D, 3F7V and 3F5W resemble each other and 3F7V is shown in magenta) structures. V76 and G77 are reorientated in the nonconductive state. b Comparison of conductive (PDB: 1K4C, black) and flipped (PDB: 2ATK [21] and 3OGC [22] are similar and 2ATK is shown in gray) structures. V76 and Y78 are reorientated in the flipped conformation. The S2 and S4 binding sites are labeled
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Fig3: Activated, inactivated, and flipped SF structures of KcsA, viewed along the membrane plane. a Comparison of conductive (PDB: 1K4C, black) and nonconductive (PDB: 1K4D, 3F7V and 3F5W resemble each other and 3F7V is shown in magenta) structures. V76 and G77 are reorientated in the nonconductive state. b Comparison of conductive (PDB: 1K4C, black) and flipped (PDB: 2ATK [21] and 3OGC [22] are similar and 2ATK is shown in gray) structures. V76 and Y78 are reorientated in the flipped conformation. The S2 and S4 binding sites are labeled

Mentions: The transmembrane part of KcsA. a The atomic structure of KcsA in the conductive state (PDB: 1K4C) viewed along the membrane plane. The pore-forming domain consists of the outer helix (magenta), loop regions (green), pore helix (blue), SF (yellow), and inner helix (orange). The conducted K+ ions are represented by purple balls with surrounding water molecules in red. EC is extracellular and IC is intracellular for short. The glycine hinge (Gly99) and the helical bundle are labeled. b, c The enlarged view of the boxed area in (a) containing the SF and the extracellular entryway. The K+ ions are in two configurations, either in S2 and S4 (b) or S1 and S3 (c) during conduction. The water molecules occupy the vacant ion positions in S1 and S3 (b) or in S2 and S4 (c). Other ions are located in the extracellular entryway (either S0 (b) or Sext (c)) and in the central cavity (Sc (a)). For clarity, only two monomers opposite to each other are shown. The amino acid sequence of the SF is labeled. All figures (Figs. 1, 2, 3, 4, 5, 6, 7, 8) in this paper were made using Chimera [130] and GNU Image Manipulation Program (GIMP)


Structure of potassium channels.

Kuang Q, Purhonen P, Hebert H - Cell. Mol. Life Sci. (2015)

Activated, inactivated, and flipped SF structures of KcsA, viewed along the membrane plane. a Comparison of conductive (PDB: 1K4C, black) and nonconductive (PDB: 1K4D, 3F7V and 3F5W resemble each other and 3F7V is shown in magenta) structures. V76 and G77 are reorientated in the nonconductive state. b Comparison of conductive (PDB: 1K4C, black) and flipped (PDB: 2ATK [21] and 3OGC [22] are similar and 2ATK is shown in gray) structures. V76 and Y78 are reorientated in the flipped conformation. The S2 and S4 binding sites are labeled
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4565861&req=5

Fig3: Activated, inactivated, and flipped SF structures of KcsA, viewed along the membrane plane. a Comparison of conductive (PDB: 1K4C, black) and nonconductive (PDB: 1K4D, 3F7V and 3F5W resemble each other and 3F7V is shown in magenta) structures. V76 and G77 are reorientated in the nonconductive state. b Comparison of conductive (PDB: 1K4C, black) and flipped (PDB: 2ATK [21] and 3OGC [22] are similar and 2ATK is shown in gray) structures. V76 and Y78 are reorientated in the flipped conformation. The S2 and S4 binding sites are labeled
Mentions: The transmembrane part of KcsA. a The atomic structure of KcsA in the conductive state (PDB: 1K4C) viewed along the membrane plane. The pore-forming domain consists of the outer helix (magenta), loop regions (green), pore helix (blue), SF (yellow), and inner helix (orange). The conducted K+ ions are represented by purple balls with surrounding water molecules in red. EC is extracellular and IC is intracellular for short. The glycine hinge (Gly99) and the helical bundle are labeled. b, c The enlarged view of the boxed area in (a) containing the SF and the extracellular entryway. The K+ ions are in two configurations, either in S2 and S4 (b) or S1 and S3 (c) during conduction. The water molecules occupy the vacant ion positions in S1 and S3 (b) or in S2 and S4 (c). Other ions are located in the extracellular entryway (either S0 (b) or Sext (c)) and in the central cavity (Sc (a)). For clarity, only two monomers opposite to each other are shown. The amino acid sequence of the SF is labeled. All figures (Figs. 1, 2, 3, 4, 5, 6, 7, 8) in this paper were made using Chimera [130] and GNU Image Manipulation Program (GIMP)

Bottom Line: Potassium channels ubiquitously exist in nearly all kingdoms of life and perform diverse but important functions.The general properties shared by all potassium channels are introduced first, followed by specific features in each class.Our purpose is to help readers to grasp the basic concepts, to be familiar with the property of the different domains, and to understand the structure and function of the potassium channels better.

View Article: PubMed Central - PubMed

Affiliation: Department of Biosciences and Nutrition, Karolinska Institutet, Novum, 14183, Huddinge, Sweden. Qie.Kuang@ki.se.

ABSTRACT
Potassium channels ubiquitously exist in nearly all kingdoms of life and perform diverse but important functions. Since the first atomic structure of a prokaryotic potassium channel (KcsA, a channel from Streptomyces lividans) was determined, tremendous progress has been made in understanding the mechanism of potassium channels and channels conducting other ions. In this review, we discuss the structure of various kinds of potassium channels, including the potassium channel with the pore-forming domain only (KcsA), voltage-gated, inwardly rectifying, tandem pore domain, and ligand-gated ones. The general properties shared by all potassium channels are introduced first, followed by specific features in each class. Our purpose is to help readers to grasp the basic concepts, to be familiar with the property of the different domains, and to understand the structure and function of the potassium channels better.

Show MeSH