Forum 10/24/2002

“Gap junction structure comparison – Having fun in a nightmare”

Anchi Cheng, Research Associate – Department of Cell Biology, The Scripps Research Institute, La Jolla, CA

Gap junctions couple adjacent cells to mediate direct intercellular communication.  The protein making up the gap junction is called connexin.  My connexin project involves locating the 13 kD C-terminus that is the structure element for pH gating in connexin 43.  The idea was to compare the 3-D density map of a full length protein to that of a C-terminus truncated form.  It qualifies as a nightmare because, after 5 years and total of overall close to 60 preps, the difference was minimal.  We believe, among other possibilities, that the C-terminus is disordered under the experimental condition.  However painful the process is to prepare and to collect data from 2-D crystals, one day’s work still typically amounts to images containing 120,000 copies of molecule, aligned.  I will present my dream for automatic crystal selection, which should make the experience more enjoyable.

Leave a Reply