Cloning and partial sequence analysis of a Mycoplasma synoviae DNA fragment encoding epitopes shared with the major adhesin P1 protein of Mycoplasma pneumoniae.

Polyclonal antibodies specific for the adhesin P1 protein of Mycoplasma pneumoniae were used to screen an expression library of M. synoviae genomic DNA constructed in the expression vector lambda gt11. Following several cycles of immunoscreening using the anti-P1 antiserum, a lambda gt11 recombinant clone containing 3.9 kilobase pairs (kbp) of M. synoviae DNA was identified and isolated from the expression library. Expression of the recombinant clone (designated MS-1) in Escherichia coli Y1089 followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the crude E. coli lysates revealed the presence of two novel proteins. Two antibodies that recognize the adhesin polypeptide--chicken anti-M. synoviae antibodies and anti-P1 antiserum--reacted with both proteins on immunoblots. Partial sequence analysis of the M. synoviae DNA in clone MS-1 and computer comparison of the predicted amino-acid sequences with existing protein sequence files revealed homology with the adhesin P1 protein of M. pneumoniae.