Mycoplasma bovis Encodes a Novel LRR Lipoprotein That Undergoes Proteolytic Processing and Binds Host Extracellular Matrix Components.

causes serious infections in ruminants, leading to huge economic losses. Lipoproteins are key components of the mycoplasma membrane and are believed to function in nutrient acquisition, adherence, enzymatic interactions with the host, and induction of the host's immune response to infection. Many genes of have not been assigned functions, in part because of their low sequence similarity with other bacteria, making it difficult to extrapolate gene functions. This study examined functions of a surface-localized leucine-rich repeat (LRR) lipoprotein encoded by of PG45. Homologs of MbfN were detected as 48-kDa peptides by Western blotting in all the strains of included in this study, with the predicted 70-kDa full-length polypeptide detected in some strains. Sequence analysis of the gene revealed the absence in some strains of a region encoding the carboxyl-terminal 147 amino acids found in strain PG45, which could account for the variation detected by immunoblotting. analysis of MbfN suggested that it may have an adhesion-related function. binding assays confirmed MbfN to be a fibronectin and heparin-binding protein. Disruption of in PG45 significantly reduced ( = 0.033) the adherence of PG45 to MDBK cells , demonstrating the role of MbfN as an adhesin. Experimental validation of the putative functions of genes in will advance our understanding of the basic biology of this economically important pathogen and is crucial in developing prevention strategies. This study demonstrated the extracellular matrix binding ability of a novel immunogenic lipoprotein of , and the role of this protein in adhesion by suggests that it could play a role in virulence.