5m2n
From Proteopedia
Crystal Structure of Elongator subunit Elp2
Structural highlights
Function[ELP2_YEAST] Acts as component of the RNA polymerase II elongator complex, which is a major histone acetyltransferase component of the RNA polymerase II (RNAPII) holoenzyme and is involved in transcriptional elongation. Association with elongating RNAPII requires a hyperphosphorylated state of the RNAPII C-terminal domain (CTD). Elongator binds to both naked and nucleosomal DNA, can acetylate both core and nucleosomal histones, and is involved in chromatin remodeling. It acetylates histones H3, preferentially at 'Lys-14', and H4, preferentially at 'Lys-8'. It functions as a gamma-toxin target (TOT); disruption of the complex confers resistance to Kluyveromyces lactis toxin zymocin (pGKL1 killer toxin). May also be involved in sensitiviy to Pichia inositovora toxin. May be involved in tRNA modification. ELP2 is dispensable for the complex integrity and, in vitro, is not required for complex HAT activity. It is not required for the association of the complex with nascent RNA transcript. Independently, ELP2 may be involved in polarized exocytosis. Is required for an early step in synthesis of 5-methoxycarbonylmethyl (mcm5) and 5-carbamoylmethyl (ncm5) groups present on uridines at the wobble position in tRNA.[1] [2] [3] [4] [5] [6] [7] [8] Publication Abstract from PubMedThe highly conserved eukaryotic Elongator complex performs specific chemical modifications on wobble base uridines of tRNAs, which are essential for proteome stability and homeostasis. The complex is formed by six individual subunits (Elp1-6) that are all equally important for its tRNA modification activity. However, its overall architecture and the detailed reaction mechanism remain elusive. Here, we report the structures of the fully assembled yeast Elongator and the Elp123 sub-complex solved by an integrative structure determination approach showing that two copies of the Elp1, Elp2, and Elp3 subunits form a two-lobed scaffold, which binds Elp456 asymmetrically. Our topological models are consistent with previous studies on individual subunits and further validated by complementary biochemical analyses. Our study provides a structural framework on how the tRNA modification activity is carried out by Elongator. Architecture of the yeast Elongator complex.,Dauden MI, Kosinski J, Kolaj-Robin O, Desfosses A, Ori A, Faux C, Hoffmann NA, Onuma OF, Breunig KD, Beck M, Sachse C, Seraphin B, Glatt S, Muller CW EMBO Rep. 2016 Dec 14. pii: e201643353. PMID:27974378[9] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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