4DRX

GTP-Tubulin in complex with a DARPIN

Summary for 4DRX

• Entry DOI: 10.2210/pdb4drx/pdb
• Descriptor: Tubulin alpha chain, Tubulin beta chain, Designed ankyrin repeat protein (DARPIN) D1, ... (6 entities in total)
• Functional Keywords: alpha-tubulin, beta-tubulin, gtpase, microtubule, darpin, subtilisin, tubulin, tubulin digested with subtilisin, cell cycle
• Biological source: ARTIFICIAL GENE; More
• Total number of polymer chains: 6
• Total formula weight: 232407.57

Authors

Pecqueur, L.,Gigant, B.,Knossow, M. (deposition date: 2012-02-17, release date: 2012-07-11, Last modification date: 2023-09-13)

Primary citation

Pecqueur, L.,Duellberg, C.,Dreier, B.,Jiang, Q.,Wang, C.,Pluckthun, A.,Surrey, T.,Gigant, B.,Knossow, M.
A designed ankyrin repeat protein selected to bind to tubulin caps the microtubule plus end.
Proc.Natl.Acad.Sci.USA, 109:12011-12016, 2012

PubMed Abstract: Microtubules are cytoskeleton filaments consisting of αβ-tubulin heterodimers. They switch between phases of growth and shrinkage. The underlying mechanism of this property, called dynamic instability, is not fully understood. Here, we identified a designed ankyrin repeat protein (DARPin) that interferes with microtubule assembly in a unique manner. The X-ray structure of its complex with GTP-tubulin shows that it binds to the β-tubulin surface exposed at microtubule (+) ends. The details of the structure provide insight into the role of GTP in microtubule polymerization and the conformational state of tubulin at the very microtubule end. They show in particular that GTP facilitates the tubulin structural switch that accompanies microtubule assembly but does not trigger it in unpolymerized tubulin. Total internal reflection fluorescence microscopy revealed that the DARPin specifically blocks growth at the microtubule (+) end by a selective end-capping mechanism, ultimately favoring microtubule disassembly from that end. DARPins promise to become designable tools for the dissection of microtubule dynamic properties selective for either of their two different ends.

PubMed: 22778434
DOI: 10.1073/pnas.1204129109

Experimental method

X-RAY DIFFRACTION (2.22 Å)