Abstract
We are working on Na+/H+ antiporters from cyanobacteria. We showed that NhaP type Na+/H+ antiporter from a halotolerant cyanobacterium Aphanothece halophytica (ApNHaP1) exhibited high Na+/H+ antiporter activity over a wide range of pH. We also showed that ApNapA1 exhibited strongly pH dependent exchange activities. Recently, multi-component Na+/H+ antiporter (Mrp) was found in a cyanobacterium. We isolated Mrp genes from Synechococcus elongatus PCC 7942 and Aphanothece halophytica. Biochemical and physiological functions of these antiporters were examined and their results will be presented.
