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Why is the microtubule lattice helical?

Wednesday, February 13, 2008 - 11:15am - 12:15pm
Lind 409
Imre Jánosi (Eötvös Loránd University (ELTE))
Microtubules polymerize from identical tubulin heterodimers, which form a helical lattice pattern for each known species. This pattern always has left-handed chirality, but it is not known why. Since tubulin, similar to other proteins, evolved for a purpose, the question of the title of this talk appears to be meaningful. In a computer simulation that explores the ‘counterfactual biology’ of microtubules without helicity, we demonstrate that these have the same mechanical properties as Nature’s microtubules with helicity. Thus only a dynamical reason for helicity is left as potential explanation. We propose that helicity solves ‘the problem of the blind mason’, i.e. how to correctly build a structure, guided only by the shape of the bricks. This answer in turn raises some new questions for researchers to address.