Structural thermal adaptation of β-tubulins from the Antarctic psychrophilic protozoan Euplotes focardii

摘要: Tubulin dimers of psychrophilic eukaryotes can polymerize into microtubules at 4°C, a temperature which from mesophiles disassemble. This unique capability requires changes in the primary structure and/or post-translational modifications tubulin subunits. To contribute to understanding mechanisms responsible for microtubule cold stability, here we present computational structural analysis based on molecular dynamics (MD) and experimental data three β-tubulin isotypes, named EFBT2, EFBT3, EFBT4, Antarctic protozoon Euplotes focardii that optimal growth reproduction is 4°C. In comparison E. crassus, mesophilic species, EFBT4 possess amino acid substitutions confer different flexible properties polypeptide, as well an increased hydrophobicity regions involved interdimeric contacts may overcome destabilizing effect temperatures. The MD indicated all isotypes display flexibility formation longitudinal lateral during polymerization. We also investigated role process cilia formation. characteristics tertiary structures seem with distinct dynamic functional properties.