Structural Cues for Understanding eEF1A2 Moonlighting

• Published in: Chembiochem : a European journal of chemical biology Vol. 22; no. 2; pp. 374 - 391
• Main Authors: Carriles, Alejandra A., Mills, Alberto, Muñoz‐Alonso, María‐José, Gutiérrez, Dolores, Domínguez, Juan M., Hermoso, Juan A., Gago, Federico
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 15.01.2021
• Subjects: Actin; Anchoring; Autophagy; Binding; Carboxylates; Cell membranes; Crystal structure; Dimers; Disabilities; EEF1A2 gene; Epilepsy; Gene mapping; Grooves; Interfaces; Kinases; MAP kinase; mass spectrometry; Molecular modelling; multifunctional protein; Muscles; Mutation; Phagocytosis; Phosphatidylethanolamine; post-translational modification; Protein structure; Proteins; Skeletal muscle; translation elongation factor; Tumorigenesis; X-ray crystallography; X-ray crystallography; protein structure; mass spectrometry; post-translational modification; multifunctional protein; translation elongation factor
• ISSN: 1439-4227; 1439-7633
• DOI: 10.1002/cbic.202000516

Spontaneous mutations in the EEF1A2 gene cause epilepsy and severe neurological disabilities in children. The crystal structure of eEF1A2 protein purified from rabbit skeletal muscle reveals a post‐translationally modified dimer that provides information about the sites of interaction with numerous binding partners, including itself, and maps these mutations onto the dimer and tetramer interfaces. The spatial locations of the side chain carboxylates of Glu301 and Glu374, to which phosphatidylethanolamine is uniquely attached via an amide bond, define the anchoring points of eEF1A2 to cellular membranes and interorganellar membrane contact sites. Additional bioinformatic and molecular modeling results provide novel structural insight into the demonstrated binding of eEF1A2 to SH3 domains, the common MAPK docking groove, filamentous actin, and phosphatidylinositol‐4 kinase IIIβ. In this new light, the role of eEF1A2 as an ancient, multifaceted, and articulated G protein at the crossroads of autophagy, oncogenesis and viral replication appears very distant from the “canonical” one of delivering aminoacyl‐tRNAs to the ribosome that has dominated the scene and much of the thinking for many decades. Beyond translation elongation: The X‐ray crystal structure of the G protein eEF1A2, purified from rabbit skeletal muscle and solved as a head‐to‐tail dimer, plus complementary bioinformatic and modeling work help understand the effect of mutations responsible for severe neurodevelopmental disorders in children, inform about the locations of two membrane anchoring sites per monomer, and contribute to unraveling the subtleties of the intricate eEF1A2 interactome.