SEQUENCE-ANALYSIS AND CHARACTERIZATION OF THE HMW GENE-CLUSTER OF MYCOPLASMA-PNEUMONIAE

Mycoplasma pneumoniae (Mp) cytadherence requires the proper anchoring of cytadhesin proteins in the mycoplasmal membrane at an attachment or ganelle through their interaction with a cytoskeleton-like network of accessory proteins that includes HMW1 and HMW3. Approximately 8.25 kb of Mp DNA was sequenced, beginning at the 3' end of the hmw3 gene and continuing through hmw1. Comparison of the resulting deduced amino aci d (aa) sequence with N terminus and internal peptide aa sequences from purified HMW1 permitted definitive identification of hmw1. HMW1 was c haracterized with respect to structure, hydrophobicity, possible phosp hoacceptor sites and expression of the Mp recombinant protein in Esche richia coli. In addition, HMW1 membrane topography was examined for an tibody accessibility on the mycoplasmal surface. hmw3 and hmw1 flank f our open reading frames (ORFs) spanning. approximately 4.3 kb and in t he same orientation as the hmw genes. The sequences of their deduced p roducts were evaluated for likely structural features and comparison w ith protein data banks. Finally, the Mp rpsD analog was identified imm ediately downstream from hmw1.