Rol de los puentes hidrógeno en la detección de pH por la histidin-quinasa DesK

Abstract

This dataset corresponds to experiments conducted to study the response of transmembrane histidine kinase (DesK) to pH. The two-component system DesK-DesR regulates the synthesis of unsaturated fatty acids in the soil bacteria Bacillus Subtilis. This system is activated at low temperature and maintains membrane lipid fluidity upon temperature variations. We conducted five independent experiments and found that DesK also responds to pH, and studied the mechanism of pH sensing. We propose that a helix linking the transmembrane region with the cytoplasmic catalytic domain is involved in pH sensing.This helix contains several glutamate, lysine, and arginine residues At neutral pH, the linker forms an alpha helix that is stabilized by hydrogen bonds in the i, i + 4 register and thus favors the kinase state. At low pH, protonation of glutamate residues breaks salt bridges, which results in helix destabilization and interruption of signaling. This mechanism inhibits unsaturated fatty acid synthesis and rigidifies the membrane when Bacillus grows in acidic conditions. (2020-08-14). The paper has been published: A Transmembrane Histidine Kinase Functions as a pH Sensor. Bortolotti A, Vazquez DB, Almada JC, Inda ME, Drusin SI, Villalba JM, Moreno DM, Ruysschaert JM, Cybulski LE. Biomolecules. 2020 Aug 14;10(8):1183. doi: 10.3390/biom10081183. doi: 10.3390/biom10081183