Recombinant E.coli ssaA1 protein

The SsaA1 recombinant protein is derived from the SsaA1 gene, which encodes a key component of the Type III Secretion System (T3SS) in *Salmonella enterica* serovars, particularly those associated with systemic infections. This secretion system, located within Salmonella Pathogenicity Island 2 (SPI-2), is critical for bacterial survival and replication within host cells, enabling the pathogen to evade immune responses and establish persistent infections. The SsaA1 protein functions as a structural and regulatory element of the SPI-2 T3SS apparatus, facilitating the translocation of effector proteins into host cells to manipulate cellular processes, such as vesicle trafficking and immune signaling.

Recombinant SsaA1 is typically produced using heterologous expression systems, such as *Escherichia coli*, through cloning and overexpression of the ssaA1 gene. Purification methods often involve affinity chromatography (e.g., His-tag systems) followed by refolding or buffer exchange to ensure proper protein conformation. Its production enables detailed study of SPI-2 T3SS assembly, host-pathogen interactions, and virulence mechanisms. Researchers utilize SsaA1 recombinant protein to investigate immune responses, including antibody production and T-cell activation, as well as to develop diagnostic tools or subunit vaccines targeting *Salmonella*. Additionally, it serves as a molecular tool to dissect the role of T3SS in intracellular bacterial survival, offering insights into broader antimicrobial strategies. Studies on SsaA1 contribute to understanding Gram-negative bacterial pathogenesis and the design of therapeutics against antibiotic-resistant strains.