Genetic analysis reveals two very different K+ transport systems in E. coli. The Kdp system has a high affinity for K+, is driven by ATP, and consists entirely of inner membrane proteins. The genetic expression of the Kdp system is regulated by the turgor pressure. In contrast, the TrkA system has a low affinity for K+, is genetically complex, and requires the protonmotive force in addition to ATP for energization. Transport activity of both systems is osmotically regulated; reduced turgor pressure stimulates K+ uptake.
ASJC Scopus subject areas
- Molecular Biology