Template-free 13-protofilament microtubule-MAP assembly visualized at 8 A resolution.
J Cell Biol
; 191(3): 463-70, 2010 Nov 01.
Article
em En
| MEDLINE
| ID: mdl-20974813
ABSTRACT
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 Å 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.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Neuropeptídeos
/
Proteínas Associadas aos Microtúbulos
/
Microtúbulos
Limite:
Humans
Idioma:
En
Revista:
J Cell Biol
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Reino Unido
País de publicação:
EEUU
/
ESTADOS UNIDOS
/
ESTADOS UNIDOS DA AMERICA
/
EUA
/
UNITED STATES
/
UNITED STATES OF AMERICA
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US
/
USA