Characterization of the gene for a 30-kilodalton adhesion-related protein of Mycoplasma pneumoniae

Abstract

A previously identified trypsin-resistant surface protein of Mycoplasma pneumoniae clusters at the tip organelle of virulent mycoplasmas and appears to be essential for cytadherence and virulence. Monoclonal antibodies generated against this protein were used to identify positive recombinant clones from M. pneumoniae genomic DNA libraries. The structural gene was sequenced and contained an open reading frame of 825 nucleotides that encoded a protein of 275 amino acids with a calculated molecular mass of 29,743 Da. This protein (P30) contained three types of repeat sequences at the carboxy end, each consisting of six amino acids. In addition, the protein was proline rich (20.7%) and exhibited significant amino acid homology with the P1 cytadhesin of M. pneumoniae and with several matrix-associated eucaryotic proteins.

Mycoplasma pneumoniae—an emerging extra-pulmonary pathogen

“…P1, P30, P116 and HMW1-3 comprise a group of membrane proteins associated with Mycoplasma cyto-adherence [20][21][22], some of which concentrate on a single attachment tip organelle ( Fig. 1) found at the surface of Mycoplasma [23][24][25]. Alteration or the absence of any of these proteins results in Mycoplasma becoming avirulent [26,27].…”

Sialic Acids in Molecular and Cellular Interactions

“…However, P1 is expressed on both adhesive and nonadhesive M. pneumoniae cells and multiple forms have been found, possibly caused by homologous but not identical copies of the gene on the 182 S0RGE KELM AND ROLAND SCHAUER bacterial genome (Su et al, 1988(Su et al, , 1990(Su et al, , 1991(Su et al, , 1993. Also, a role of other accessory molecules has been suggested, such as a 30-kDa protein Dallo et al, 1990), that may be required for the presentation of P1 in a binding-competent state.…”

Mechanism of antigenic variation in Mycoplasma pulmonis: interwoven, site‐specific DNA inversions

“…Surface antigens having tandem repetitive domains seem to be particularly prevalent in mycoplasmas and their phylogenetic relatives such as streptococci and clostridia (Fischetti et aL, 1991;Wren, 1991). Tandem repetitive domains of significant size are present in the VIp protein family of Mycoplasma hyorhinis (Yogev et aL, 1991) and in proteins from the human pathogens Mycoplasma pneumoniae (Dallo et aL, 1990), Mycoplasma hominis (Ladefoged et aL, 1995) and Ureaplasma urealyticum (Zheng et aL, 1995). Proteins with tandem repetitive domains are frequently involved with cell-cell interactions, and in many cases, the repeating units are thought to be ligand-binding domains.…”