THE BREAST-CANCER GENE-PRODUCT TSG101 - A REGULATOR OF UBIQUITINATION

Sequence analysis is a powerful tool to obtain structural and function al information about genes and their products. Here we show that TSG1O 1, a gene subjected to somatic mutations in breast cancer, contains an amino terminal domain that is a homologue of ubiquitin conjugating en zymes (UBCs) and not, as previously proposed, DNA-binding domains. As the UBC active site residue is replaced in the TSG1O1 sequence in a si milar manner to several other members of the UBC family, we propose a role for TSG1O1 in regulating the ubiquitination of short-lived gene p roducts.