Cloning and characterization of a gene for a 19kDa fibrinogen‐binding protein from Staphylococcus aureus

Abstract

Summary: Staphylococcus aureus has been shown to interact specifically with fibrinogen. Three different extracellular fibrinogen‐binding proteins, two of which have coagulase activity, are produced by S. aureus strain Newman. The role of these fibrinogen‐binding proteins during staphylococcal colonization and infection has not yet been fully elucidated. Here we describe the cloning, sequencing and expression of a gene for a 19kDa fibrinogen‐binding protein. This gene, called fib, encodes a 165‐amino‐acid polypeptide, including a 29‐amino‐acid signal sequence. The recombinant protein, which has an estimated molecular mass of 15.9kDa, bound fibrinogen and was recognized by a polyclonal antiserum against the native Fib protein. Homologies between the Fib protein and the fibrinogen‐binding domain of coagulase suggest that amino acids within this domain are involved in the binding to fibrinogen.