Figure 12.

Diagram of nucleoside (red boxes and arrows) and nucleobase (orange boxes and arrows) transporters in Trichomonas vaginalis. HA, high affinity; LA, (relatively) low affinity. Substrates indicated in brackets are of substantial lower affinity than those without brackets. Arrows indicate bi-directional traffic (equilibrative) but it is not yet known whether (some of) the transporters are active transporters, which would imply mono-directionality. The guanine uptake may be mediated by a separate transporter, which would be designated NT-g. However, at this juncture the possibility that the guanine uptake is mediated by one of the other transporters rather than a separate gene product cannot be excluded.