Mrp superfamily explained

The Na⁺ Transporting Mrp Superfamily is a superfamily of integral membrane transport proteins.

It includes the TC families:

2.A.63 - The Monovalent Cation (K⁺ or Na⁺):Proton Antiporter-3 (CPA3) Family

3.D.1 - The H⁺ or Na⁺-translocating NADH Dehyrogenase (NDH) Family

3.D.9 - The H⁺-translocating F₄₂₀H₂ Dehydrogenase (F₄₂₀H₂DH) Family

Mrp of Bacillus subtilis is a 7 subunit Na⁺/H⁺ antiporter complex (TC# 2.A.63.1.4). All subunits are homologous to the subunits in other members of this monovalent cation (K⁺ or Na⁺):proton antiporter-3 (CPA3) family as well as subunits in the archaeal hydrogenases (TC#s 3.D.1.4.1 and 3.D.1.4.2), which share several subunits with NADH dehydrogenase subunits (3.D.1). The largest subunits of the Mrp complex (MrpA and MrpD) are homologous to subunits in NADH dehydrogenases (NDHs): ND2, ND4 and ND5 in the fungal NADH dehydrogenase complex and most other NDHs, as well as subunits in the F₄₂₀H₂ dehydrogenase of Methanosarcina mazei (TC#3.D.9.1.1).^[1] These homologous subunits may catalyze Na⁺/K⁺ and/or H⁺ transport.

See also

• Transporter Classification Database

Notes and References

1. Zickermann. Volker. Wirth. Christophe. Nasiri. Hamid. Siegmund. Karin. Schwalbe. Harald. Hunte. Carola. Brandt. Ulrich. 2015-01-02. Structural biology. Mechanistic insight from the crystal structure of mitochondrial complex I. Science . 347. 6217. 44–49. 10.1126/science.1259859. 1095-9203. 25554780.