Sortase as a tool in structural biology
Sortases are a family of membrane–anchored transpeptidases expressed by Gram–positive bacteria. Sortase A catalyzes the cleavage of C-terminal recognition motif (LPXTG) of multiple structurally unrelated proteins followed by formation of an amide bond with the peptidoglycan layer of the bacteria. Since Sortases are widely distributed among a variety of bacterial pathogens and required for virulence, Sortases represent a promising therapeutic target for the development of novel anti-infective agents.
Sortase A is extensively used as a biotechnology tool for a variety of protein modifications and immobilization by Sortase-mediated protein ligation. The transpeptidase activity of Sortase A is used to generate fusion proteins in vitro, where the recognition motif (LPXTG) is added in C-terminus of the protein of interest.
The catalytic activity of viral proteases and Sortase A can be monitored using FRET-based assays. Substrates are available as catalog peptides.