I have some questions regarding building microtubules:

  1. Do alpha and beta monomers always exist as dimers when they are bonding to form tubulin?

  2. When tubulin structure is destroyed, do alpha and beta monomers fall apart as dimers or monomers? and does it happen at the positive or negative end?


1 Answer 1


Microtubules polymerise from and depolymerise into alpha-beta-tubulin dimers.

Both happen on both ends, see this question: At which end does polymerization of microtubules occur?.

  • $\begingroup$ Thanks for your answer. Wouldn’t it be more favorable to connect monomers rather than dimers ? because then it wouldn’t matter how the dimers are oriented to get alpha on top of beta. $\endgroup$
    – Bayan
    Commented Apr 9, 2018 at 11:32
  • $\begingroup$ The orientation of each monomer would still need to be the same, regardless of the order in which the bonds are made, because none of the molecules involved are symmetric. I don't know though how it's better to have dimers around as building blocks rather than monomers. $\endgroup$
    – Armatus
    Commented Apr 9, 2018 at 13:39

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