When present on multicopy plasmids confers increased resistance to fluoroquinolone antibiotics such as ciprofloxacin and sparfloxacin but not the quinolone nalidixic acid (PubMed:11709313). Forms a structure that exhibits size, shape and electrostatic similarity to B-form DNA; it may bind to DNA gyrase which is postulated to protect it from fluoroquinolones (By similarity). Homodimer. Probably interacts with DNA gyrase. Each subunit forms a right-handed beta-helix with 8 complete coils that stack upon each other. Decreased resistance to fluoroquinolone antibiotics ciprofloxacin and sparfloxacin. Belongs to the pentapeptide repeat protein family.