The X-ray crystal structure of NapA, a Na+/H+ antiporter from Thermus thermophilus, in an active, outward-facing state is reported; comparisons to the structure of a related transporter in a low pH/inactivated, inward-facing state show the conformational changes that occur when the membrane protein moves from an inward-facing to an outward-facing state, suggesting that Na+/H+ antiporters operate by a two-domain rocking bundle model.
- Chiara Lee
- Hae Joo Kang
- David Drew
