Expanding the Substrate Tolerance of Biotin Ligase through Exploration of Enzymes from Diverse Species

摘要

Escherichia coli biotin ligase (BirA) has been harnessed for numerous biotechnological applications, including protein labeling, purification, and immobilization. BirA catalyzes the ATP-dependent covalent ligation of biotin onto a lysine side chain of a 15-amino acid recognition sequence called the "acceptor peptide" (AP). Previously, we showed that BirA could be applied to site-specific protein labeling on the surface of living cells by making use of a ketone isostere of biotin that could be ligated to AP fusion proteins, then derivatized with hydrazide or hydroxylamine probes.