Projection structure of full length connexin 43 by electron cryo-crystallography.
We previously used electron cryo-crystallography to determine the three-dimensional structure of recombinant gap junction channels formed by a C-terminal truncation mutant of Cx43 (11). The dodecameric channel is formed by the end-to-end docking of two hexameric connexons, each comprised of 24 transmembrane alpha-helices. We have now generated two-dimensional crystals of the recombinant, full-length channel, as well as crystals in which the C-tail has been completely removed by trypsin digestion. Projection density maps at 7.5 A resolution closely resemble our previous analysis of the C-terminal truncation mutant (9). A difference map between the full length and trypsin-treated channels suggests that there are small but significant shifts in protein density upon removal of the C-tail.
Cheng
Anchi
A
Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
Schweissinger
Daniel
D
Dawood
Farah
F
Kumar
Nalin
N
Yeager
Mark
M
D000818:Animals; D018031:Connexin 43 / Q000737:chemistry*; D020285:Cryoelectron Microscopy / Q000379:methods*; D003460:Crystallization; D017629:Gap Junctions / Q000737:chemistry*; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry
D018031:Connexin 43; D011994:Recombinant Proteins