6qk7 | pdb_00006qk7
Elongator catalytic subcomplex Elp123 lobe
Structural highlights
FunctionELP1_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. Independently, ELP3 may be involved in polarized exocytosis. It is required for the polarized localization of GTPase-activating protein SEC2. 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 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 A. 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. Molecular basis of tRNA recognition by the Elongator complex.,Dauden MI, Jaciuk M, Weis F, Lin TY, Kleindienst C, Abbassi NEH, Khatter H, Krutyholowa R, Breunig KD, Kosinski J, Muller CW, Glatt S Sci Adv. 2019 Jul 10;5(7):eaaw2326. doi: 10.1126/sciadv.aaw2326. eCollection 2019, Jul. PMID:31309145[9] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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