Fibronectin binding protein A

Fibronectin binding protein A (FnBPA) is a bacterial adhesin found predominantly in Staphylococcus aureus. This protein plays a crucial role in the pathogenesis of Staphylococcus aureus by facilitating the attachment of the bacteria to fibronectin, a large glycoprotein that is a part of the extracellular matrix in host tissues. FnBPA targets fibronectin through an interaction that leads to the invasion of host cells and evasion of the immune response, contributing to infections such as wound infections, septic arthritis, and endocarditis.

Structure

FnBPA is characterized by an N-terminal signal sequence followed by an A domain that binds to fibronectin. The protein also contains repeated domains that are thought to increase the binding affinity to fibronectin. The C-terminal region of FnBPA contains cell wall sorting signals that anchor the protein to the peptidoglycan of the bacterial cell wall.

Function

The primary function of FnBPA is to mediate the adhesion of Staphylococcus aureus to fibronectin, which is abundant in wounded tissue and on cell surfaces. This interaction not only facilitates colonization by the bacteria but also enables it to invade host cells. The binding of FnBPA to fibronectin exposes binding sites for integrins on the host cell surface, leading to the internalization of the bacteria by the host cells.

Clinical Significance

The ability of Staphylococcus aureus to bind fibronectin via FnBPA is an important factor in the pathogenesis of several types of infections. Targeting FnBPA with vaccines or inhibitors has been proposed as a strategy to prevent or treat infections caused by Staphylococcus aureus. Research into the detailed mechanism of FnBPA and its interactions with host tissues continues to be a significant area of study in the field of infectious diseases.

See Also

• Staphylococcus aureus
• Adhesin
• Extracellular matrix
• Infectious disease