Top Level Name

  ⌊ Superfamily (core) Radical SAM

    ⌊ Subgroup elongater protein-like

     ⌊ Family ELP3-like

Total 100% <100%
Functional domains 1038 1020 18
UniProtKB 1137 1118 19
GI 2255 2214 41
Structures 0
Reactions 0
Functional domains of this family were last updated on June 10, 2017
New functional domains were last added to this family on July 5, 2014

The archaeal protein, the homolog of the third subunit of the eukaryotic Elongator complex (Elp3), is catalyses the tRNA wobble uridine modification at C5. The same reaction as the eukaryotic Elongator complex. The proposed mechanism of action by Elp3 represents an unprecedented chemistry performed on acetyl-CoA in which the methyl group of the acetly-CoA is activated by the 5'-deoxyadenosyl radical. This then adds to the uridine of tRNA.

The elongator complex is a major component of the RNA polymerase II (RNAPII) holoenzyme responsible for transcriptional elongation. It 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'. ELP3 is required for the complex integrity and for the association of the complex with nascent RNA transcript. ELP3 is thought to act as a highly conserved histone acetyltransferase (HAT) capable of acetylating core histones in vitro, however, it is clearly a multi-domain protein. The HAT activity is thought to be present only in the C-terminal GNAT domain (histone acyltransferase domain). Recent work by Defraia et al. suggest that both the histone acetyltransferase and radical S-adenosylmethionine domains are essential for function, although the exact role of the Radical SAM domain is still unclear. Defraia et al. suggest that the radical SAM domain is important for the structural integrity of the protein complex, and in yeast (previously demonstrated). However, an alternative may be that ELP3 binds and cleave SAM, as seen in the archaea M. jannaschii. It has also been shown in previous studies that the mouse ELP3 does not require the histone acyltransferase domain for zygotic paternal genome demethylation.

Wittschieben BO, Otero G, de Bizemont T, Fellows J, Erdjument-Bromage H, Ohba R, Li Y, Allis CD, Tempst P, Svejstrup JQ

A novel histone acetyltransferase is an integral subunit of elongating RNA polymerase II holoenzyme

▸ Abstract

Mol Cell 1999;4(1):123-128 | PubMed ID: 10445034

Paraskevopoulou C, Fairhurst SA, Lowe DJ, Brick P, Onesti S

The Elongator subunit Elp3 contains a Fe4S4 cluster and binds S-adenosylmethionine

▸ Abstract

Mol Microbiol. 2006;59(3):795-806 | PubMed ID: 16420352

Defraia CT, Wang Y, Yao J, Mou Z

Elongator subunit 3 positively regulates plant immunity through its histone acetyltransferase and radical S-adenosylmethionine domains

▸ Abstract

BMC Plant Biol 2013;13(None):102-None | PubMed ID: 23856002

Greenwood C, Selth LA, Dirac-Svejstrup AB, Svejstrup JQ

An iron-sulfur cluster domain in Elp3 important for the structural integrity of elongator

▸ Abstract

J Biol Chem 2009;284(11):141-149 | PubMed ID: 18986986

Okada Y, Yamagata K, Hong K, Wakayama T, Zhang Y

A role for the elongator complex in zygotic paternal genome demethylation

▸ Abstract

Nature 2010;463(7280):554-558 | PubMed ID: 20054296

Selvadurai K, Wang P, Seimetz J, Huang RH

Archaeal Elp3 catalyzes tRNA wobble uridine modification at C5 via a radical mechanism

▸ Abstract

Nat Chem Biol 2014;10(10):810-812 | PubMed ID: 25151136

Glatt S, Zabel R, Kolaj-Robin O, Onuma OF, Baudin F, Graziadei A, Taverniti V, Lin TY, Baymann F, Séraphin B, Breunig KD, Müller CW

Structural basis for tRNA modification by Elp3 from Dehalococcoides mccartyi

▸ Abstract

Nat Struct Mol Biol 2016;23(9):794-802 | PubMed ID: 27455459

No notes.

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