2XRP: Human Doublecortin N-DC Repeat (1MJD) and Mammalian Tubulin (1JFF and 3HKE) Docked into the 8-Angstrom Cryo-EM Map of Doublecortin- Stabilised Microtubules

Microtubule-associated proteins (MAPs) are essential for regulating and organizing cellular microtubules (MTs). However, our mechanistic understanding of MAP function is limited by a lack of detailed structural information. Using cryo-electron microscopy and single particle algorithms, we solved the 8 A structure of doublecortin (DCX)-stabilized MTs. Because of DCX's unusual ability to specifically nucleate and stabilize 13-protofilament MTs, our reconstruction provides unprecedented insight into the structure of MTs with an in vivo architecture, and in the absence of a stabilizing drug. DCX specifically recognizes the corner of four tubulin dimers, a binding mode ideally suited to stabilizing both lateral and longitudinal lattice contacts. A striking consequence of this is that DCX does not bind the MT seam. DCX binding on the MT surface indirectly stabilizes conserved tubulin-tubulin lateral contacts in the MT lumen, operating independently of the nucleotide bound to tubulin. DCX's exquisite binding selectivity uncovers important insights into regulation of cellular MTs.
PDB ID: 2XRPDownload
MMDB ID: 86390
PDB Deposition Date: 2010/9/18
Updated in MMDB: 2010/11
Experimental Method:
electron microscopy
Resolution: 8.2  Å
Source Organism:
Bos taurus
Similar Structures:
Biological Unit for 2XRP: nonameric; determined by author and by software (PISA)
Molecular Components in 2XRP
Label Count Molecule
Proteins (9 molecules)
Tubulin Beta-2b Chain(Gene symbol: TUBB2B)
Molecule annotation
Tubulin Alpha-1d Chain(Gene symbol: TUBA1D)
Molecule annotation
Neuronal Migration Protein Doublecortin(Gene symbol: DCX)
Molecule annotation
Chemicals (8 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB