Studying Flexible Elements of Microtubule Structure Using Cryo-Electron Microscopy and Molecular Modeling: Mission Possible?

Microtubules are the basic elements of the cytoskeleton of eukaryotic cells. Due to their multifunctionality, unique structure, and high mechanical rigidity, they remain a favorite object of research using various microscopy techniques, including cryo-electron microscopy. Despite impressive advances in visualizing the microtubule lattice and flexible elements of their structure—individual protofilaments at the assembling or disassembling ends, as well as regulatory unstructured peptides known as C-terminal “tails”—the latter are still poorly visualized. In this paper, the authors discuss progress in the application of cryo-electron microscopy and tomography to the study of these structural elements as well as the role and potential of molecular modeling methods for the analysis and interpretation of the obtained experimental data.