High-affinity potassium transporter. Induced by low K(+) concentrations (PubMed:28420751). Expression is regulated by cyclic di-AMP (c-di-AMP), via the ydaO riboswitch (PubMed:20511502, PubMed:24141192, PubMed:28420751). High external concentrations of K(+) stimulate an increase in the production of c-di-AMP, which binds to the riboswitch and prevents kimA expression (PubMed:28420751). Belongs to the amino acid-polyamine-organocation (APC) superfamily.