FIGURE 2.

Functional expression of LdNT1. 1 permeases with crippling mutations (A) or mutations that resulted in moderate but significant inhibition of transport activity (B). Uptake of [³H]adenosine (Ado) (1 μm, 30s) and [³H]uridine (Urd) (5 μm, 30 s) were determined at room temperature (∼22 °C) and expressed as percentages of the uptake by wild type LdNT1.1. The level of background binding was subtracted from each point by measuring the uptake of radiolabeled ligand by parasites treated with 1% formaldehyde. Transport results represent means ± standard deviations for three independent experiments. For each mutant, two independent clones were isolated and tested in parallel to confirm each result (data not shown).