Identification and characterization of hitherto unknown Mycoplasma pneumoniae proteins.

Eleven hitherto unknown Mycoplasma pneumoniae proteins were identified and characterized with respect to their size and subcellular location. This was carried out through the construction of in vitro gene fusions between a modified mouse dehydrofolate reductase (dhfr) gene and selected regions (cosmid clones) of the M. pneumoniae genome and expressing them in Escherichia coli. Positive clones were identified using antibodies against specific fractions of M. pneumoniae. The deduced protein sequences of 11 out of 30 clones did not show significant homologies to known proteins in protein data-bank searches. Monospecific antibodies against these 11 fusion proteins were used to determine the size and cellular location of the corresponding M. pneumoniae proteins by immunoscreening Western blots of SDS-acrylamide gels from M. pneumoniae cell extracts.