Ehrlichia chaffeensis expresses an immunoreactive protein homologous to the Escherichia coli GroEL protein.

A clone expressing a 58-kDa protein reactive with human convalescent-phase serum was isolated from a recombinant library of Ehrlichia chaffeensis, the etiologic agent of human ehrlichiosis. Sequencing identified two open reading frames, one encoding a 10.3-kDa polypeptide consisting of 94 amino acids and another encoding a 58-kDa polypeptide consisting of 550 amino acids. The sequences of the 10.3- and 58-kDa polypeptides were homologous to those of the Escherichia coli GroES and GroEL heat shock proteins, respectively.