CELL BIOLOGY:
Structure of Key Cytoskeletal Protein Tubulin Revealed
Elizabeth Pennisi
At last month's annual meeting of the American Society for Cell Biology in Washington, D.C., two researchers dazzled their audience with the first detailed view of tubulin: a map of the protein's structure down to 3.7 angstroms, sufficient to see the precise arrangement of its amino acids. Cell biologists had been waiting eagerly to get a good look at tubulin because it is the building block of one of the major components of the cell's internal skeleton, the microtubules, which play key roles in many cell functions. Yet, despite years of biochemical and biophysical studies, researchers do not yet fully understand such critical aspects of microtubule function as how their tubulin subunits assemble and disassemble--information also needed to help understand how cell division is controlled. The new structure should help resolve those issues, because it reveals how the two subunits that make up tubulin interact with each other and with other molecules. And in related work, another team has solved the structure of FtsZ, a bacterial protein that appears to be the evolutionary precursor of tubulin.
