Hostname: page-component-586b7cd67f-l7hp2 Total loading time: 0 Render date: 2024-12-01T10:57:57.265Z Has data issue: false hasContentIssue false
  • English
  • Français

Structure of a Recombinant Gap Junction Channel at 7Å Resolution

Published online by Cambridge University Press:  02 July 2020

V.M. Unger ,
D. W. Entrikin ,
X. Guan ,
N.M. Kumar ,
N.B. Gilula  and
M. Yeager
V.M. Unger
Affiliation:
The Scripps Research Institute, La Jolla, CA, 92037
D. W. Entrikin
Affiliation:
The Scripps Research Institute, La Jolla, CA, 92037
X. Guan
Affiliation:
The Scripps Research Institute, La Jolla, CA, 92037
N.M. Kumar
Affiliation:
The Scripps Research Institute, La Jolla, CA, 92037
N.B. Gilula
Affiliation:
The Scripps Research Institute, La Jolla, CA, 92037
M. Yeager
Affiliation:
The Scripps Research Institute, La Jolla, CA, 92037
Get access

Extract

Gap junction membrane channels mediate the electrical and metabolic coupling between cells. The channels are formed by the end-to-end docking of two hemichannels (connexons), each of which is formed by a hexameric cluster of protein subunits (connexins). The principal gap junction protein in the heart, α1 connexin (also designated Cx43), mediates action potential propagation between cells in order to synchronize cardiac contraction.

We recently utilized electron cryo-microscopy and image analysis to examine frozen-hydrated two-dimensional (2D) crystals of a recombinant, truncated α1- connexin (α1Cx263T). The projection map at 7Å resolution revealed that each 30kD connexin subunit has a transmembrane α-helix that lines the aqueous pore and a second α-helix in close contact with the membrane lipids [Nature Struct. Biol. 4: 39-43 (1997)]. The distribution of densities allowed us to propose a model in which the two apposing connexons that form the channel are staggered by ∼30°. Furthermore, apparent non-crystallographic twofold axes predicted that the two apposing connexons adopt identical conformations.

Type
High Resolution Protein Structures from Electron Crystallography
Information
Microscopy and Microanalysis , Volume 4 , Issue S2: Proceedings: Microscopy & Microanalysis '98, Microscopy Society of America 56th Annual Meeting, Microbeam Analysis Society 32nd Annual Meeting, Atlanta, Georgia July 12-16, 1998 , July 1998 , pp. 464 - 465
Copyright
Copyright © Microscopy Society of America

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)