Fig 6.

Cross-linking of TbpB and TbpA to form high-molecular-weight complexes depends on production of TbpA. Gonococci were grown under iron-depleted conditions in the presence of photoactivatable cross-linkers. Following UV irradiation (+), whole-cell lysates were prepared. Samples that were not exposed to UV irradiation (−) were included as negative controls. Strains tested include FA19 (wild type), FA6747 (TbpB⁺ TbpA⁻), MCV839 (TbpB LSAC TbpA⁺), and MCV843 (TbpB ΔGly TbpA⁺). Proteins were separated by SDS-PAGE and transferred to nitrocellulose. Blots were probed with hTf-HRP (A), anti-TbpB serum (B), or anti-TbpA serum (C). Approximate positions of molecular mass markers are indicated on the left.