Binding of human Cdc123 to eIF2γ.
J Struct Biol
; 215(3): 108006, 2023 09.
Article
in En
| MEDLINE
| ID: mdl-37507029
ABSTRACT
Eukaryotic initiation factor 2 (eIF2) plays a key role in protein synthesis and in its regulation. The assembly of this heterotrimeric factor is facilitated by Cdc123, a member of the ATP grasp family that binds the γ subunit of eIF2. Notably, some mutations related to MEHMO syndrome, an X-linked intellectual disability, affect Cdc123-mediated eIF2 assembly. The mechanism of action of Cdc123 is unclear and structural information for the human protein is awaited. Here, the crystallographic structure of human Cdc123 (Hs-Cdc123) bound to domain 3 of human eIF2γ (Hs-eIF2γD3) was determined. The structure shows that the domain 3 of eIF2γ is bound to domain 1 of Cdc123. In addition, the long C-terminal region of Hs-Cdc123 provides a link between the ATP and Hs-eIF2γD3 binding sites. A thermal shift assay shows that ATP is tightly bound to Cdc123 whereas the affinity of ADP is much smaller. Yeast cell viability experiments, western blot analysis and two-hybrid assays show that ATP is important for the function of Hs-Cdc123 in eIF2 assembly. These data and recent findings allow us to propose a refined model to explain the mechanism of action of Cdc123 in eIF2 assembly.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Saccharomyces cerevisiae Proteins
/
Mental Retardation, X-Linked
Type of study:
Prognostic_studies
Limits:
Humans
Language:
En
Journal:
J Struct Biol
Journal subject:
BIOLOGIA MOLECULAR
Year:
2023
Document type:
Article
Affiliation country:
France