%0 Journal Article %A Phonimdaeng, Prasart %A O’Reilly, Mary %A O’Toole, Paul W. %A Foster, Timothy J. %T Molecular Cloning and Expression of the Coagulase Gene of Staphylococcus aureus 8325-4 %D 1988 %J Microbiology, %V 134 %N 1 %P 75-83 %@ 1465-2080 %R https://doi.org/10.1099/00221287-134-1-75 %I Microbiology Society, %X The gene coding for coagulase (coa) was cloned from Staphylococcus aureus 8325-4 in a λ replacement vector in Escherichia coli. Coagulase (plasma-clotting) activity was measured in λ coa lysates and an immunoreactive protein of 60 kDa was detected by Western immunoblotting with anti-coagulase serum. This protein comigrated with the major immunoreactive protein in supernatants of S. aureus 8325-4. The coa gene was subcloned in pUC vectors. One recombinant expressed a 60 kDa immunoreactive protein and plasma-clotting activity. A putative β-galactosidase-coagulase fusion protein and truncated peptides were expressed by variants formed by subcloning. These results are consistent with previously published biochemical data that the prothrombin-binding domain of coagulase is located in the N-terminus of the protein. The cloned coa gene was transferred into S. aureus on a shuttle plasmid. Expression of coagulase was higher in a strain with a mutation in the agr locus, which controls the level of several exoproteins in S. aureus, suggesting that agr normally regulates coagulase expression negatively. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-134-1-75