UBIQUITIN: A single ubiquitin molecule, with thicker tubes representing the more flexible parts of the molecule PHOTO RESEARCHERS, INC., PHANTATOMIX
In 1974 and 1975, a group led by Gideon Goldstein at New York University discovered and sequenced a 76-amino-acid protein from bovine thymus cells that appeared to be important in stimulating immune-cell function. But as they continued to characterize the protein, like a bad contaminant, they found it everywhere—in every tissue of the human body, and in cell cultures from worms, other animals, plants, and even bacteria. The authors surmised that the protein must be “a universal constituent of living cells,” and consequently named it ubiquitin. Later it became apparent that the ubiquitin found in bacterial cultures came from the yeast extracts on which they were cultured, leading to the realization that ubiquitin was limited to eukaryotic cells. For several years, little more was learned ...
