A PROTEIN (M9) ASSOCIATED WITH MONOCLONAL ANTIBODY-MEDIATED AGGLUTINATION OF MYCOPLASMA-GALLISEPTICUM IS A MEMBER OF THE PMGA FAMILY

A 62-kDa cell surface antigen (M9) of Mycoplasma gallisepticum PG31 th at mediates antibody-induced agglutination of the organism was purifie d and subjected to N-terminal amino-acid sequencing. A 999-bp region o f the cDNA encoding the M9 protein was generated by reverse transcript ion-PCR, and its nucleotide sequence was determined. PCR primers based on this sequence were used to screen a genomic DNA library of PG31. A full-length M9 protein-encoding gene was isolated and sequenced, reve aling 96% nucleotide identity with the pMGA1.1 gene of M. gallisepticu m S6. Sequence analyses of the M9 gene and banking open reading frames that encode other pMGA family members suggest that a tandemly repeate d GAA sequence may influence pMGA gene expression.