Molecular and biochemical analysis of a 105 kDa Mycoplasma gallisepticum cytadhesin protein (MGP1)

Date of Completion

January 1998


Biology, Genetics|Biology, Microbiology




A gene (MGP1) from Mycoplasma gallisepticum with homology to the P1 cytadherence gene of Mycoplasma pneumoniae has been identified. The mgp1 gene is a 2895 bp ORF encoding a protein with a predicted molecular mass of 105 kDa. Nucleotide sequence analysis of the mgp1 gene revealed 45% homology to M. pneumoniae P1 and 46% homology to M. genitalium MgPa. It has a 64% A + T content compared to 46% and 60% for P1 and MgPa respectively. As with P1 and MgPa ORFs, MGP1 is a central gene in a multi-gene operon, but unlike P1 and MgPa, MGP1 does not possess repeat sequences.^ MGP1 is a surface exposed, trypsin sensitive protein. It is capable of exhibiting antigenic variation as shown by in vitro passage of M. gallisepticum in the presence of hyperimmune serum raised against MGP1. Attachment inhibition assay using Fab fragments of MGP1 antibodies inhibited attachment to chicken trachea by 64% indicating that MGP1 plays a role in adherence of M. gallisepticum to host cells. ^