Temperature Sensing by Bacterial Membranes

SAITA, E; ALBANESI, D; LUCIA PORRINI; DE MENDOZA D; MANSILLA, MC

Singapur

Congreso; 15th International Congress of Bacteriology & Applied Microbiology, International Union of Microbiological Societies; 2017

International Union of Microbiological Societies-Singapore Society for Microbiology and Biotechnology

Objectives: To analyze the structural features of themembrane-bound cold sensor-histidin kinase, DesK, from Bacillussubtilis in the two mainfunctional states of the effector domain to obtain new insights on how theprimary cold signal is sensed by the transmembrane (TM) region and transmittedto the effector domain.Methods: We used genetic, biochemical, structural andcomputational studies to dissect several aspects on wild type DesK mutant andtruncated versions of DesK, pushing forward a more general understanding of itsown structure/function relationship.Results: We found that reversible formation of a two helixcoiled-coil in the fifth TM segment and the N-terminus of the cytoplasmicdomain is essential for the sensing and transduction mechanism of DesK.Conclusion: We conclude that thecatalytic output of DesK is tuned by a delicate balance between hydrationpotentials. Coiled-coil stability and exposure of hydrophobic surface patchesat their cytoplasmic coiled coil and at the N-terminal and C-terminal sides of the TM helices