ISOLATION AND CHARACTERIZATION OF TRANSPOSON TN4001-GENERATED, CYTADHERENCE-DEFICIENT TRANSFORMANTS OF MYCOPLASMA-PNEUMONIAE AND MYCOPLASMA-GENITALIUM

Cytadherence and subsequent parasitism of host cells by the human path ogens, Mycoplasma pneumoniae and Mycoplasma genitalium, are mediated b y adhesins and adherence-related accessory proteins. In this report we demonstrate the use of transposon Tn4001 to generate Tn-induced trans formants displaying cytadherence-deficient characteristics. Mycoplasma pneumoniae Tn-generated transformant, designated 8R, lacked the high- molecular weight adherence-accessory proteins HMW1/4 and was deficient in hemadsorption and cytadherence capabilities. In transformant 8R, T n4001 was not localized in or near the hmw1 gene or in the upstream ad hesin (p30/hmw3) locus, suggesting an alternate site associated with t he regulation of hmw1 gene expression. Sequence analysis identified th e transposon insertion site at the crl locus previously reported, alth ough the protein characteristics of transformant 8R differed from the earlier described transformants. The M. genitalium Tn-transformant, de signated G26, was also defective in hemadsorption and cytadherence. Ho wever, transformant G26 synthesized adhesins P140 and P32 suggesting t hat Tn4001 transposed into a new gene or site previously unlinked to c ytadherence, namely ORF MG032. This study demonstrates the utility of Tn4001 mutagenesis for both M. pneumoniae and M. genitalium which, in the latter case, has special relevance in light of the recent complete characterization of its Continuous total genomic sequence.