Analysis, expression and prevalence of the Mycobacterium tuberculosis homolog of bacterial virulence regulating proteins

We have previously reported the identification of a gene from Mycobacterium tuberculosis, H(37)Rv, which on the basis of its nucleotide sequence encod ed a protein product of 38 kDa. This 38-Kda mycobacterial protein designate d as VirS exhibits homology with the VirF protein of Shigella, the VirFy pr otein of Yersinia and the Cfad, Rns and FapR proteins from various enteroto xigenic Escherichia coli strains. In this communication, we show the close sequence and structural similarities of the VirS protein with VirF, VirFy, Cfad, Rns and FapR and describe the results of our studies on the character ization of the virS gene promoter and its expression in E. coli and mycobac teria. virS was present exclusively in the species belonging to the M. tube rculosis complex as revealed by Southern blot and PCR analysis. Our finding s suggest the involvement of virS in the regulation of pathogenesis of M. t uberculosis. (C) 1999 Published by Elsevier Science B.V. All rights reserve d.