"We needed to keep our samples extremely stable during the imaging process in order to get the resolution we wanted," says Nogales. To this end, she and her colleagues used taxol to lock their samples into fixed positions for imaging. That the taxol would bind to their crystals is in part a confirmation that their structural model of tubulin is accurate.
The Berkeley Lab is a U.S. Department of Energy national laboratory located in Berkeley, California. It conducts unclassified scientific research and is managed by the University of California.
An image of the tubulin protein model as well as a high-resolution 1.8 mg version of the same image can be downloaded from the Web. The iillustration, a ribbon diagram based on the 3.7 angstrom resolution model of tubulin developed by Berkeley Lab scientists, shows the protein to be a dimer consisting of two monomers that are almost identical in structure. Each monomer is formed by a core of two beta sheets (blue and green) surrounded by helices, and each binds to a guanine nucleotide (pink). In addition to a nucleotide binding site, each monomer also has two other binding sites, one for proteins, and one for the anti-cancer drug taxol.
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Contact: Lynn Yarris
lcyarris@lbl.gov
510-486-5375
DOE/Lawrence Berkeley National Laboratory
8-Jan-1998
