9G0P

Xenopus laevis undecorated microtubule - 14 protofilament, 3-start helix

Summary for 9G0P

• Entry DOI: 10.2210/pdb9g0p/pdb
• Related: 9FVJ 9G0O 9G0Q 9G0R 9G0S 9G0T
• EMDB information: 50942
• Descriptor: Tubulin beta-4 chain, Tubulin alpha chain, GUANOSINE-5'-DIPHOSPHATE, ... (5 entities in total)
• Functional Keywords: microtubule tubulin cytoskeleton filament, protein fibril
• Biological source: Xenopus laevis (African clawed frog); More
• Total number of polymer chains: 12
• Total formula weight: 605830.37

Authors

Troman, L.A.,Moores, C.A. (deposition date: 2024-07-08, release date: 2025-01-15, Last modification date: 2025-02-12)

Primary citation

Troman, L.,de Gaulejac, E.,Biswas, A.,Stiens, J.,Kuropka, B.,Moores, C.A.,Reber, S.
Mechanistic basis of temperature adaptation in microtubule dynamics across frog species.
Curr.Biol., 35:612-628.e6, 2025

PubMed Abstract: Cellular processes are remarkably effective across diverse temperature ranges, even with highly conserved proteins. In the context of the microtubule cytoskeleton, which is critically involved in a wide range of cellular activities, this is particularly striking, as tubulin is one of the most conserved proteins while microtubule dynamic instability is highly temperature sensitive. Here, we leverage the diversity of natural tubulin variants from three closely related frog species that live at different temperatures. We determine the microtubule structure across all three species at between 3.0 and 3.6 Å resolution by cryo-electron microscopy and find small differences at the β-tubulin lateral interactions. Using in vitro reconstitution assays and quantitative biochemistry, we show that tubulin's free energy scales inversely with temperature. The observed weakening of lateral contacts and the low apparent activation energy for tubulin incorporation provide an explanation for the overall stability and higher growth rates of microtubules in cold-adapted frog species. This study thus broadens our conceptual framework for understanding microtubule dynamics and provides insights into how conserved cellular processes are tailored to different ecological niches.

PubMed: 39798564
DOI: 10.1016/j.cub.2024.12.022

Experimental method

ELECTRON MICROSCOPY (3 Å)