This domain is found in Thermotoga maritima NusG, which interacts with RNA polymerase and other proteins to form multi-component complexes that modulate transcription. This domain is referred to as Domain II and is an additional domain inserted into the N-terminal domain [1].

1: An autoinhibited state in the structure of Thermotoga maritima NusG. Drogemuller J, Stegmann CM, Mandal A, Steiner T, Burmann BM, Gottesman ME, Wohrl BM, Rosch P, Wahl MC, Schweimer K; Structure. 2013;21:365-375. PMID:23415559