ELP3/YhcC (IPR039661)

Short name: ELP3

Overlapping homologous superfamilies

Family relationships


This entry includes proteins with a radical SAM domain and a radical SAM C-terminal extension domain. One such protein is elongator complex protein 3 (ELP3): the catalytic histone acetyltransferase subunit of the RNA polymerase II elongator complex, which is itself part of the RNA polymerase II (RNAPII) holoenzyme responsible for transcriptional elongation [PMID: 10445034]. This entry also includes protein YhcC from Escherichia coli , which binds an [4Fe-4S] cluster, coordinated with three cysteines and an exchangeable S-adenosyl-L-methionine. YhcC cleaves S-adenosyl-L-methionine into methionine and 5'-deoxyadenosine [PMID: 25117543]. Uncharacterised homologues are known from bacteria, archaea and eukaryotes.

ELP3 is required for the complex integrity and for the association of the complex with nascent RNA transcript [PMID: 10445034]. 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) [PMID: 16420352]. Studies 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 [PMID: 23856002]. The radical SAM domain is important for the structural integrity of the protein complex, as in yeast (previously demonstrated) [PMID: 18986986]. However, an alternative may be that ELP3 binds ands 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 [PMID: 20054296].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.