Plant, Animal & Microbe Genomes X Conference

January 12-16, 2002
Town & Country Convention Center
San Diego, CA

Poster: Microbial Sequencing and Genome Programs
            

MAPPING OF CILIARY ADHESIN HOMOLOGUES ON THE MYCOPLASMA HYOPNEUMONIAE GENOME

¹ Iowa State University, 1802 Elwood Drive, Ames, IA, 50011, USA

² University of Alabama at Birmingham, Birmingham, AL 35294-2170, USA

³ 3312 39th Ave. W., Seattle, WA, 98199, USA

⁴ NSW Agriculture, Elizabeth Macarthur Agricultural Institute, Camden, NSW, 2570, Australia

Mycoplasma hyopneumoniae is the causative agent of swine respiratory mycoplasmosis and consequently, is one of the most important bacterial pathogens in the swine industry worldwide. Colonization occurs by binding exclusively to the cilia of respiratory epithelial cells. Attachment to swine cilia occurs through the action of the membrane protein P97, although participation by other proteins has not been ruled out. P97 is one of several post-translational cleavage products of a 126 kDa preprotein. In the carboxy portion of the protein is a repeat region, R1, that confers the ability to bind to cilia, and it is presumed that each cleavage product containing this region can bind to cilia. How the P97 fragments maintain their association with the M. hyopneumoniae membrane surface is not known. Since other mycoplasma species contain multiple copies of their adhesin genes, it was of interest to determine if P97 is also found in multiple copies in the cell. Southern blot data suggested that there was a single copy, but genome sequence information revealed several related copies distributed around the genome. None of these copies contained a functional R1 cilium adhesin binding site, however. Also, these copies were found in two gene operons, similar to P97. Homologs to the second gene of the operon, P102, were also found in conjunction to some but not all copies of P97. Proteomic data has shown that several of the P97/P102 homologs are expressed, but their functions are unknown.