NGN domain, eukaryotic (IPR039385)

Short name: NGN_Euk

Overlapping homologous superfamilies

Domain relationships

  • NGN domain (IPR005100)
    • NGN domain, eukaryotic (IPR039385)


The N-Utilization Substance G (NusG) protein and its eukaryotic homologue, Spt5, are involved in transcription elongation and termination. NusG contains an NGN domain at its N terminus and Kyrpides Ouzounis and Woese (KOW) repeats at its C terminus. Spt5 forms an Spt4-Spt5 complex that is an essential RNA polymerase II elongation factor. NusG was originally discovered as an N-dependent antitermination enhancing activity in Escherichia coli, and has a variety of functions such as its involvement in RNA polymerase elongation and Rho-termination in bacteria. Orthologues of the NusG gene exist in all bacteria, but their functions and requirements are different. Spt5-like is homologous to the Spt5 proteins present in all eukaryotes, which is unique as it encodes a protein with an additional long carboxy-terminal extension that contains WG/GW motifs. Spt5-like, or KTF1 (KOW domain-containing Transcription Factor 1), is a RNA-directed DNA methylation (RdDM) pathway effector in plants [PMID: 11250170, PMID: 12202748].

Contributing signatures

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