Molecular basis of tRNA recognition by the Elongator complex

Abstract

The highly conserved Elongator complex modifies transfer RNAs (tRNAs) in their wobble base position, thereby regulating protein synthesis and ensuring proteome stability. The precise mechanisms of tRNA recognition and its modification reaction remain elusive. Here, we show cryo–electron microscopy structures of the catalytic subcomplex of Elongator and its tRNA-bound state at resolutions of 3.3 and 4.4 Å. The structures resolve details of the catalytic site, including the substrate tRNA, the iron-sulfur cluster, and a SAM molecule, which are all validated by mutational analyses in vitro and in vivo. tRNA binding induces conformational rearrangements, which precisely position the targeted anticodon base in the active site. Our results provide the molecular basis for substrate recognition of Elongator, essential to understand its cellular function and role in neurodegenerative diseases and cancer.

Elongator Subunit 3 (Elp3) Is Required for Zebrafish Trunk Development

“…In zebrafish, we found diminished levels of this modification in morphant zebrafish. Also, recent structural evidence strongly support the Elongator complex function is tRNA modification [36,37]. Altogether, this data strongly indicates that the primary and evolutionarily-conserved function of the…”

Alanine tRNAs Translate Environment Into Behavior in Caenorhabditis elegans

“…Recent structural and functional analysis of tRNAs processing by the yeast elongator complex indicates that the carboxymethylation (cm5) of 11 tRNAs carrying U34, including the tRNA Ala (UGC), requires the activity of the catalytic 1-2-3 sub-complex (Dauden et al, 2019). The cm5 modification will further lead to the formation of 5-methoxycarbonylmethylated (mcm5), 5-methoxycarbonylmethyl-2-thiolated (mcm5S2) and 5-carbamoylmethylated (ncm5) modified uridines.…”

“…Elongator has been implicated in a great variety of nuclear and cytoplasmic cellular functions, including transcription elongation, chromatin remodeling, exocytosis, zygotic paternal DNA demethylation, and neuronal development (Creppe et al, 2009;Okada et al, 2010;Solinger et al, 2010;Tielens et al, 2016;Dalwadi and Yip, 2018). The multifunctionality of Elongator could be partly explained by structural analysis (Dauden et al, 2017(Dauden et al, , 2019. ELP3 contains a C-terminal Lysine Acetyl Transferase (KAT) domain and a domain with sequence homology with the S-adenosylmethionine (SAM) domain.…”

Fungal Kti12 proteins display unusual linker regions and unique ATPase p-loops

“…Recent structural analyses of the enzymatic Elp3 subunit and the Elp123 subcomplex of Elongator show that the subcomplex specifically recognizes tRNAs (Glatt et al 2016 ; Dauden et al 2019 ; Lin et al 2019 ). The overall complex consists of six pairs of subunits and is built up by a symmetrical dimer of two Elp123 subcomplexes, decorated with a hexameric Elp456 ring (Glatt et al 2012 ) on one of the Elp123 lobes (Dauden et al 2017 ; Setiaputra et al 2017 ).…”