gspE

The *gspE* gene is a component of the *gsp* (general secretion pathway) operon, which encodes proteins involved in the type II secretion system (T2SS) in certain Gram-negative bacteria. This pathway facilitates the export of folded proteins across the outer membrane, following their initial translocation through the general secretion pathway (Sec-dependent system). The T2SS is critical for the secretion of enzymes, toxins, and other virulence factors that contribute to bacterial pathogenesis and environmental adaptation.

The *gspE* gene encodes a membrane protein known as the outer membrane secretin. Secretins form a trimeric complex that spans the outer membrane, forming a channel through which secreted proteins pass. This protein is essential for the assembly and stability of the secretion apparatus, as it interacts with other components like the inner membrane proteins *GspD* and *GspG*, as well as the periplasmic pilus assembly proteins. Mutations in *gspE* often result in impaired secretion, leading to defects in virulence and reduced bacterial fitness.

The *gspE* gene is widely studied in model organisms such as *Vibrio cholerae*, *Pseudomonas aeruginosa*, and *Escherichia coli*, where it plays a role in processes like biofilm formation, motility, and host colonization. Its conservation across different bacterial species highlights its importance in secretion-dependent functions. Research on *gspE* has also contributed to the development of antimicrobial strategies targeting the T2SS, offering potential avenues for combating bacterial infections.