National Institute of Animal Health, Ibaraki, Japan.
The nucleotide sequence of the Rhodococcus equi gene encoding the virulence-associated 15-17-kDa antigens, located on plasmid pREAT701, has been determined. The gene encodes a 19-kDa protein of 189 amino acids, with an Ala-rich leader signal sequence (SS). At least five SS peptidase cleavage sites were found in this region. The molecular diversity of 15-17-kDa antigens might be attributed to the multiple SS peptidase cleavage sites.