Characterization of MGC2, a Mycoplasma gallisepticum cytadhesin with homology to the Mycoplasma pneumoniae 30-kilodalton protein P30 and Mycoplasma genitalium P32

A second cytadhesin-like protein, MGC2, was identified in the avian respiratory pathogen Mycoplasma gallisepticum. The 912-nucleotide mgc2 gene encodes a 32.6-kDa protein. with 40.9 and 31.4% identity with the,M. pneumoniae P30 and M.genitalium 32 cytadhesins, respectively. Functional studies with reverse transcription-PCR, immunoblotting, double-sided immunogold labeling, and attachment inhibition assays demonstrated homology to the human mycoplasmal P30 and P32 cytadhesins. These findings suggest that there is a family of cytadhesin genes conserved among pathogenic mycoplasmas infecting widely divergent hosts.