Analysis of tandem, multiple genes encoding 30-kDa membrane proteins in Pasteurella haemolytica A1.

A number of outer membrane proteins (OMPs), including a 30-kDa protein, may be important in eliciting immunity to Pasteurella haemolytica A1, the causative agent of bovine pneumonic pasteurellosis. To better understand the nature of the 30-kDa antigen, several genes encoding this protein were sequenced. Sequence analysis revealed that three separate genes encoding similar, yet distinct, versions of the 30-kDa protein are tandemly arranged on the P. haemolytica A1 chromosome. The genes appear to be transcribed from a single promoter. The deduced amino acid sequences of the proteins encoded by these genes are similar to a 28-kDa inner membrane lipoprotein of Escherichia coli and a 28-kDa membrane protein which may contribute to the virulence of Haemophilus influenzae type b strains.