[Inversion of phototaxis in cells of Synechocystis sp. PCC 6803 determined by a mutation in the regulatory gene prqR].

Phototaxis, positive (movement toward the light source) or negative (from the light source) mediates the adaptation of cyanobacteria to varying wave lengths and illumination intensity. The transcription regulator PrqR of the family TetR is known as a repressor of the prqRA operon controlling resistance to the oxidative stress inducer methyl viologen in the cyanobacterium Synechocystis sp. PCC6803.

[The prqA and mvrA genes encoding carrier proteins control resistance to methyl viologen in the cyanobacterium Synechocystis sp. PCC6803].

Derivatives with insertional inactivation of prqA and mvrA genes were obtained and studied in the Synechocystis sp. PCC6803 wild-type strain and in the mutant Prq20 resistant to methyl viologen (MV). It was shown that the formation of resistance to MV is associated with the operation of two systems: constitutive and inducible.