Altering the Neisseria gonorrhoeae pilE Guanine Quadruplex Loop Bases Affects Pilin Antigenic Variation.

ABSTRACT: Neisseria gonorrhoeae possesses a programmed recombination system that allows the bacteria to alter the major subunit of the type IV pilus, pilin or PilE. An alternate DNA structure known as a guanine quadruplex (G4) is required for pilin antigenic variation (pilin Av). The G-C base pairs within the G4 motif are required for pilin Av, but simple mutation of the loop bases does not affect pilin Av. We show that more substantial changes to the loops, in both size and nucleotide composition, with the core guanines unchanged, decrease or abrogate pilin Av. We investigated why these loop changes might influence the efficiency of pilin Av. RecA is a recombinase required for pilin Av that can bind the pilE G4 in vitro. RecA binds different G4 structures with altered loops with varie

SUBMITTER: Prister LL 

PROVIDER: S-EPMC7750920 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature