Recombinant Human srtA protein

Sortase A (SrtA) is a calcium-dependent transpeptidase originally identified in *Staphylococcus aureus*, where it plays a critical role in anchoring surface proteins to the bacterial cell wall. This enzyme catalyzes a unique covalent bond-forming reaction by recognizing a conserved LPXTG motif in substrate proteins. SrtA cleaves the threonine-glycine (T-G) bond within this motif and links the carboxyl group of threonine to the amino group of pentaglycine cross-bridges in the cell wall, enabling surface protein display—a process vital for bacterial adhesion, immune evasion, and infection.

The recombinant form of SrtA (rSrtA) has been widely engineered for biotechnological applications due to its ability to perform site-specific ligation under mild conditions. Unlike traditional chemical conjugation methods, rSrtA enables precise, efficient, and biocompatible protein modifications, making it valuable in protein engineering, biomaterial functionalization, and therapeutic development. For example, rSrtA is employed to conjugate antibodies, peptides, or fluorescent tags to target molecules for diagnostics, drug delivery, or imaging.

Research on rSrtA has expanded to include engineered variants with enhanced catalytic activity, altered substrate specificity, or improved stability. These modifications address limitations of the wild-type enzyme, such as calcium dependency or slow kinetics, broadening its utility in synthetic biology and industrial processes. Additionally, rSrtA’s role in studying bacterial pathogenesis has fueled antimicrobial strategies targeting sortase-mediated pathways.

Overall, recombinant SrtA bridges microbiology and biotechnology, offering a versatile tool for covalent protein labeling, hybrid biomolecule assembly, and novel therapeutic design, while its study continues to inform both basic science and applied innovations.