TYPE-IV PREPILIN PEPTIDASE GENE OF NEISSERIA-GONORRHOEAE MS11 - PRESENCE OF A RELATED GENE IN OTHER PILIATED AND NONPILIATED NEISSERIA STRAINS

The assembly of type IV pili in Neisseria gonorrhoeae is a complex pro cess likely to require the products of many genes. One of these is the enzyme prepilin peptidase, which cleaves and then N methylates the pr ecursor pilin subunits prior to their assembly into pill. We have used a PCR amplification strategy to clone the N. gonorrhoeae prepilin pep tidase gene, pilD(Ng). A single copy of the gene is shown to be presen t in the chromosome. Its product promotes correct cleavage of the gono coccal prepilin in Escherichia coli cells carrying both the prepilin p eptidase gene and the pilin structural gene. PilD(Ng) also cleaves pre PulG, a type N pilin-like protein of Krebsiella oxytoca, Moreover, Pil D(Ng) complements a mutation in the gene coding for the prepilin pepti dase-like protein of K. oxytoca, pulO, partially restoring PulG-PulO-d ependent extracellular secretion of the enzyme pullulanase. Finally, w e show that genes homologous to pilD(Ng) are present and expressed in a variety of species in the genus Neisseria, including some commensal strains.