Abstract
The fit locus, encoding two proteins, FitA and FitB, was identified in a genetic screen for Neisseria gonorrhoeae determinants that affect trafficking across polarized epithelial cells. To better understand how the locus may control these activities, we have undertaken a biochemical analysis of FitA and FitB. FitA is a DNA-binding protein with a putative ribbon-helix-helix (RHH) motif. Purified FitA forms a homodimer that binds a 150 bp fit promoter sequence containing the translational start site. A putative β strand mutant of FitA, FitA(R7A), is unable to bind this DNA, supporting further that FitA is a RHH protein. FitB interacts with FitA to form a 98 kDa complex. FitA/B binds DNA with a 38-fold higher affinity than the FitA homodimer. In DNase I footprint assays, FitA/B protects a 62-bp region within the fit promoter containing the predicted -10 sequence and an 8-bp inverted repeat, TGCTATCA-N 12-TGATAGCA. FitA/BHiS is able to bind to either half-site alone with high affinity.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 12515-12524 |
| Number of pages | 10 |
| Journal | Biochemistry |
| Volume | 44 |
| Issue number | 37 |
| DOIs | |
| State | Published - Sep 20 2005 |
| Externally published | Yes |
ASJC Scopus subject areas
- Biochemistry