3-Dimensional architecture of the human multi-tRNA synthetase complex.
Nucleic Acids Res
; 48(15): 8740-8754, 2020 09 04.
Article
em En
| MEDLINE
| ID: mdl-32644155
ABSTRACT
In mammalian cells, eight cytoplasmic aminoacyl-tRNA synthetases (AARS), and three non-synthetase proteins, reside in a large multi-tRNA synthetase complex (MSC). AARSs have critical roles in interpretation of the genetic code during protein synthesis, and in non-canonical functions unrelated to translation. Nonetheless, the structure and function of the MSC remain unclear. Partial or complete crystal structures of all MSC constituents have been reported; however, the structure of the holo-MSC has not been resolved. We have taken advantage of cross-linking mass spectrometry (XL-MS) and molecular docking to interrogate the three-dimensional architecture of the MSC in human HEK293T cells. The XL-MS approach uniquely provides structural information on flexibly appended domains, characteristic of nearly all MSC constituents. Using the MS-cleavable cross-linker, disuccinimidyl sulfoxide, inter-protein cross-links spanning all MSC constituents were observed, including cross-links between eight protein pairs not previously known to interact. Intra-protein cross-links defined new structural relationships between domains in several constituents. Unexpectedly, an asymmetric AARS distribution was observed featuring a clustering of tRNA anti-codon binding domains on one MSC face. Possibly, the non-uniform localization improves efficiency of delivery of charged tRNA's to an interacting ribosome during translation. In summary, we show a highly compact, 3D structural model of the human holo-MSC.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Conformação Proteica
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Complexos Multiproteicos
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Aminoacil-tRNA Sintetases
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Conformação de Ácido Nucleico
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Estados Unidos