Protein Domain : TrkH potassium transport family IPR004772

Type	Family
Description	The Trk system is a low to medium affinity potassium uptake system, widely found in both in bacteria and archaea, where the uptake of K(+) is believed to be linked to H(+) symport [ ]. The core Trk system consists of two proteins, the integral membrane K(+)-translocating protein TrkH (or TrkG), and the regulatory NAD-binding peripheral membrane protein TrkA [, , ]. In Escherichia coli the activity of TrkH is dependent on the ATP-binding protein SapD (also known as TrkE) which is part of the SapABCDF ABC transporter, involved in putrescine export []. Not all Trk systems are dependent on SapD however - it is thought that these may utilise ATP-binding proteins from other ABC transporters [].Also included in this entry is the homologous subunit J of a V-type Na(+) ATP synthase found in some bacteria such as Enterococcus hirae. The function of this subunit is unknown, but as K(+) transport is dependent on the activity of the V-type Na(+) ATP synthase in this organism, it may function to exchange Na(+) for K(+) [ ].
Short Name	TrkH