MRPB Antibody – Rabbit Polyclonal

Function: Mrp complex is a Na+/H+ antiporter that is considered to be the major Na+ excretion system in B.subtilis. Has a major role in Na+ resistance and a minor role in Na+- and K+-dependent pH homeostasis as compared to TetB. MrpA may be the actual Na+/H+ antiporter, although the six other Mrp proteins are all required for Na+/H+ antiport activity and Na+ resistance. MrpA is required for initiation of sporulation when external Na+ concentration increases. Also transports Li+ but not K+, Ca2+ or Mg2+. Ref.3 Ref.5

Subunit structure: Forms a heterooligomeric complex that consists of seven subunits: MrpA, MrpB, MrpC, MrpD, MrpE, MrpF and MrpG. Ref.6

Subcellular location: Cell membrane; Multi-pass membrane protein

Potential.

Miscellaneous: Mrp-dependent antiport apparently occurs by a secondary, proton motive force-dependent mechanism, but the similarity of several Mrp proteins to membrane-embedded subunits of energy-coupled NADH dehydrogenase complexes raises the possibility that there is a capacity for electron transport that could provide a primary energy coupling option for Mrp functions.

Sequence similarities: Belongs to the CPA3 antiporters (TC 2.A.63) subunit B family. [View classification]