The comP locus of Neisseria gonorrhoeae encodes a type IV prepilin that isdispensable for pilus biogenesis but essential for natural transformation

The expression of type IV pill (Tfp) by Neisseria gonorrhoeae has been show n to be essential for natural genetic transformation at the level of sequen ce-specific uptake of DNA, All previously characterized mutants defective i n this step of transformation either lack Tfp or are altered in the express ion of Tfp-associated properties, such as twitching motility, autoagglutina tion and the ability to bind to human epithelial cells. To examine the basi s for this relationship, we identified potential genes encoding polypeptide s sharing structural similarities to PiIE, the Tfp subunit, within the N. g onorrhoeae genome sequence database. We found that disruption of one such g ene, designated comP (for competence-associated prepilin), leads to a sever e defect in the capacity to take up DNA in a sequence-specific manner, but does not alter Tfp biogenesis or expression of the Tfp-associated propertie s of autoagglutination, twitching motility and human epithelial cell adhere nce. Indirect evidence based on immunodetection suggests that ComP is expre ssed at very low levels relative to that of PiIE. The process of DNA uptake in gonococci, therefore, is now known to require the expression of at leas t three distinct components: Tfp, the recently identified PiIT protein and ComP.