[Systems of H+-K+-exchange in E. coli. Interplay with ATPase complex F1.F0]

A study has been made of the nature of H+-K+-exchanges in the strain E. coli AN 120 with mutation in gene uncA401 (the defect in Mg++-Ca++-ATPase) and in the strain E. coli AN 382 with mutation in gene uncB (F0 is insensitive to N,N1-dicyclohehylcarbodiimide, DCCD). It was shown in E. coli AN 120 that no ATP-dependent and DCCD-sensitive TrkA system operates, exchanging 2H+ from a cell for K+ of the medium and actuating only in the presence of a difference of osmotic pressures between the cell and the medium. At the same time the strain E. coli AN 120 possesses An ATP-independent TrkF system exchanging H+ by K+ with variable stoichiometry and inhibited by DCCD. The TrkA and TrkF systems have lost the sensitivity to DCCD in E. coli AN 382. Moreover the TrkA system in this mutant has turned insensitive to the variation of osmotic pressure in the medium, i. e. DCCD-insensitivity of the TrkA and TrkF systems as well as the osmotic sensitivity of the TrkA system are related to the F0 function. We do not exclude the chance of the ionic channel F0 being a portion of both systems of potassium accumulation.