3j7i | pdb_00003j7i
Structure of alpha- and beta- tubulin in GMPCPP-microtubules
Structural highlights
FunctionTBA1A_PIG Tubulin is the major constituent of microtubules. It binds two moles of GTP, one at an exchangeable site on the beta chain and one at a non-exchangeable site on the alpha chain. Publication Abstract from PubMedMicrotubules are dynamic polymers that stochastically switch between growing and shrinking phases. Microtubule dynamics are regulated by guanosine triphosphate (GTP) hydrolysis by beta-tubulin, but the mechanism of this regulation remains elusive because high-resolution microtubule structures have only been revealed for the guanosine diphosphate (GDP) state. In this paper, we solved the cryoelectron microscopy (cryo-EM) structure of microtubule stabilized with a GTP analogue, guanylyl 5'-alpha,beta-methylenediphosphonate (GMPCPP), at 8.8-A resolution by developing a novel cryo-EM image reconstruction algorithm. In contrast to the crystal structures of GTP-bound tubulin relatives such as gamma-tubulin and bacterial tubulins, significant changes were detected between GMPCPP and GDP-taxol microtubules at the contacts between tubulins both along the protofilament and between neighboring protofilaments, contributing to the stability of the microtubule. These findings are consistent with the structural plasticity or lattice model and suggest the structural basis not only for the regulatory mechanism of microtubule dynamics but also for the recognition of the nucleotide state of the microtubule by several microtubule-binding proteins, such as EB1 or kinesin. Conformational changes in tubulin in GMPCPP and GDP-taxol microtubules observed by cryoelectron microscopy.,Yajima H, Ogura T, Nitta R, Okada Y, Sato C, Hirokawa N J Cell Biol. 2012 Aug 6;198(3):315-22. doi: 10.1083/jcb.201201161. Epub 2012 Jul , 30. PMID:22851320[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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