FIG. 2.

Removal of iron from iron-saturated human transferrin by Y. pestis. Tf was incubated overnight with iron-starved cultures of Y. pestis Ybt⁺ KIM6+ (lane 2) or Ybt⁻ KIM6-2046.1 (lane 3). Tf was in a dialysis baggy (12,000- to 14,000-Da molecular mass cutoff), separating it from the cultures. After incubation, the various iron-saturated Tf forms were separated on 6% polyacrylamide-urea gels. Incubation of Tf with PMH growth medium (lane 1) was used as a negative control. Partially saturated Tf (lane 4) and a mixture of various forms of Tf (lane 5) were used to show mobility shifts due to iron saturation of Tf. The image is from one of two independent experiments, which yielded similar results.