Mycolyltransferase 85A (Ag85A)

Mycolyltransferase 85A, commonly referred to as Antigen 85A (Ag85A), is a key enzyme secreted by Mycobacterium tuberculosis and is a member of the Antigen 85 complex (UniProt P9WQP3). It functions as a mycolyltransferase, catalyzing the transfer of mycolic acids from trehalose monomycolate to form trehalose dimycolate (cord factor) and the mycolylarabinogalactan complex, which are essential components of the mycobacterial cell wall (PubMed: 10880320). This cell wall structure is crucial for the bacterium's survival, virulence, and resistance to host immune responses (PubMed: 15659681). Due to its essential role in maintaining cell wall integrity and its high immunogenicity, Ag85A is a prominent target for the development of novel tuberculosis treatments and vaccines, such as the MVA85A candidate (PubMed: 23395242). Inhibiting Ag85A activity leads to a compromised cell envelope, increasing the pathogen's vulnerability to antibiotics and host-mediated clearance (PubMed: 25182314). Furthermore, its ability to bind fibronectin suggests a role in the attachment of the bacteria to host cells, facilitating infection (PubMed: 10880320). As a secreted protein, it is highly accessible to the host immune system, making it a primary focus for diagnostic and therapeutic interventions.

Other names

Antigen 85AAg85AFbpAFibronectin-binding protein A32 kDa antigenAlpha-antigen

Inhibition of mycolyltransferase activity to disrupt mycobacterial cell wall assembly and integrity (PubMed: 10880320).