NGN-insert domain found between N-terminal domain (D1) and C-terminal KOW domain (DIII) repeats of some N-Utilization Substance G (NusG) N-terminal (NGN)
This family contains a unique insert (domain II, DII) found between the highly conserved N-terminal domain (NGN, domain I, D1) and C-terminal Kyrpides Ouzounis and Woese domain (KOW, domain III, DIII) repeats of some N-Utilization Substance G (NusG) N-terminal (NGN) proteins in bacteria such as Aquifex aeolicus NusG (AaeNusG). NusG was originally discovered as having an N-dependent antitermination enhancing activity in Escherichia coli, and has since been shown to have a variety of functions such as being involved in RNA polymerase elongation and Rho-termination. Orthologs of NusG gene exist in bacteria, but their functions and requirements are diverse. The function of DII is as yet unknown, and belongs to Domains of Unknown Function 1312 (DUF1312).
Jiyao W et al.(2023). "The conserved domain database in 2023.",