Why is the microtubule lattice helical?
Microtubules polymerize from identical tubulin heterodimers, which form a helical lattice pattern that is the microtubule. This pattern always has left-handed chirality, but it is not known why. But as tubulin, similar to other proteins, evolved for a purpose, the question of the title of this artcile 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 find 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.
Hunyadi
Viktória
V
Department of Physics of Complex Systems, Eötvös University, P.O. Box 32, H-1518 Budapest, Hungary.
Chrétien
Denis
D
Flyvbjerg
Henrik
H
Jánosi
Imre M
IM
D001696:Biomechanical Phenomena; D019281:Dimerization; D004548:Elasticity; D008870:Microtubules / Q000737:chemistry* / Q000648:ultrastructure; D008958:Models, Molecular; D017433:Protein Structure, Secondary; D014404:Tubulin / Q000737:chemistry
D014404:Tubulin