ジャーナル: J Mol Biol / 年: 2016 タイトル: Hexadecameric structure of an invertebrate gap junction channel. 著者: Atsunori Oshima / Tomohiro Matsuzawa / Kazuyoshi Murata / Kazutoshi Tani / Yoshinori Fujiyoshi / 要旨: Innexins are invertebrate-specific gap junction proteins with four transmembrane helices. These proteins oligomerize to constitute intercellular channels that allow for the passage of small signaling ...Innexins are invertebrate-specific gap junction proteins with four transmembrane helices. These proteins oligomerize to constitute intercellular channels that allow for the passage of small signaling molecules associated with neural and muscular electrical activity. In contrast to the large number of structural and functional studies of connexin gap junction channels, few structural studies of recombinant innexin channels are reported. Here we show the three-dimensional structure of two-dimensionally crystallized Caenorhabditis elegans innexin-6 (INX-6) gap junction channels. The N-terminal deleted INX-6 proteins are crystallized in lipid bilayers. The three-dimensional reconstruction determined by cryo-electron crystallography reveals that a single INX-6 gap junction channel comprises 16 subunits, a hexadecamer, in contrast to chordate connexin channels, which comprise 12 subunits. The channel pore diameters at the cytoplasmic entrance and extracellular gap region are larger than those of connexin26. Two bulb densities are observed in each hemichannel, one in the pore and the other at the cytoplasmic side of the hemichannel in the channel pore pathway. These findings imply a structural diversity of gap junction channels among multicellular organisms.
A: 168.3393 Å / B: 158.6151 Å / C: 322.5 Å α: 90.0 ° / β: 90.0 ° / γ: 121.7 °
CCP4マップ ヘッダ情報:
mode
Image stored as Reals
Å/pix. X/Y/Z
2.4396956521739
2.5176984126984
2.5
M x/y/z
69
63
129
origin x/y/z
0.000
0.000
0.000
length x/y/z
168.339
158.615
322.500
α/β/γ
90.000
90.000
121.700
start NX/NY/NZ
-34
-31
-64
NX/NY/NZ
69
63
129
MAP C/R/S
2
1
3
start NC/NR/NS
-31
-34
-64
NC/NR/NS
63
69
129
D min/max/mean
-7.991
4.120
-0.017
-
添付データ
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試料の構成要素
-
全体 : The N-terminal deleted C. elegans innexin-6
全体
名称: The N-terminal deleted C. elegans innexin-6
要素
試料: The N-terminal deleted C. elegans innexin-6
タンパク質・ペプチド: innexin-6
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超分子 #1000: The N-terminal deleted C. elegans innexin-6
超分子
名称: The N-terminal deleted C. elegans innexin-6 / タイプ: sample / ID: 1000 / 詳細: The sample was reconstituted in lipid bilayers. / 集合状態: hexadecamer / Number unique components: 1