Three-dimensional structure of basal body triplet revealed by electron cryo-tomography.
EMBO J
; 31(3): 552-62, 2012 Feb 01.
Article
em En
| MEDLINE
| ID: mdl-22157822
ABSTRACT
Basal bodies and centrioles play central roles in microtubule (MT)-organizing centres within many eukaryotes. They share a barrel-shaped cylindrical structure composed of nine MT triplet blades. Here, we report the structure of the basal body triplet at 33 Šresolution obtained by electron cryo-tomography and 3D subtomogram averaging. By fitting the atomic structure of tubulin into the EM density, we built a pseudo-atomic model of the tubulin protofilaments at the core of the triplet. The 3D density map reveals additional densities that represent non-tubulin proteins attached to the triplet, including a large inner circular structure in the basal body lumen, which functions as a scaffold to stabilize the entire basal body barrel. We found clear longitudinal structural variations along the basal body, suggesting a sequential and coordinated assembly mechanism. We propose a model in which δ-tubulin and other components participate in the assembly of the basal body.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Tomografia com Microscopia Eletrônica
/
Microtúbulos
Idioma:
En
Revista:
EMBO J
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Estados Unidos