Download MendeleyThe unusual active site of Gal6/bleomycin hydrolase can act as a carboxypeptidase, aminopeptidase, and peptide ligase.
Zheng, W., Johnston, S.A., Joshua-Tor, L.(1998) Cell 93: 103-109
- PubMed: 9546396
- DOI: https://doi.org/10.1016/s0092-8674(00)81150-2
- Primary Citation of Related Structures:
1A6R, 3GCB - PubMed Abstract:
The Gal6 protease is in a class of cysteine peptidases identified by their ability to inactivate the anti-cancer drug bleomycin. The protein forms a barrel structure with the active sites embedded in a channel as in the proteasome. In Gal6 the C termini lie in the active site clefts. We show that Gal6 acts as a carboxypeptidase on its C terminus to convert itself to an aminopeptidase and peptide ligase. The substrate specificity of the peptidase activity is determined by the position of the C terminus of Gal6 rather than the sequence of the substrate. We propose a model to explain these diverse activities and Gal6's singular ability to inactivate bleomycin.
Organizational Affiliation:
Center for Biomedical Inventions, Department of Medicine, University of Texas-Southwestern Medical Center, Dallas 75235-8573, USA.
