Fig 7.

Possible mechanisms of GGI integration into the meningococcal chromosome. (A) Integration by XerCD site-specific recombination. The GGI as a mobile element contained a sequence homologous to the dif sequence. The site-specific recombinases XerC and XerD acted on the dif sequence in the GGI and dif sequence in the meningococcal chromosome, resulting in integration of the GGI. The gene NMA1385 is still present in this strain with the GGI. (B) Integration by homologous recombination. After uptake of the GGI from gonococci by a meningococcal cell, the GGI is integrated into the chromosome by homologous recombination at yheS and ung. The gene NMA1385 is no longer present.