This domain is found at the C-terminal end of Transcriptional regulator (TetR/AcrR family) from Thermus thermophilus (SbtR) [2] and similar sequences predominantly found in actinobacteria. This domain is found associated with Pfam:PF00440.

1: Crystal structure of a putative transcriptional regulator SCO0520 from Streptomyces coelicolor A3(2) reveals an unusual dimer among TetR family proteins. Filippova EV, Chruszcz M, Cymborowski M, Gu J, Savchenko A, Edwards A, Minor W; J Struct Funct Genomics. 2011;12:149-157. PMID:21625866

2: Structure and function of a TetR family transcriptional regulator, SbtR, from thermus thermophilus HB8. Agari Y, Sakamoto K, Yutani K, Kuramitsu S, Shinkai A; Proteins. 2013;81:1166-1178. PMID:23408580

3: Mechanistic and Structural Insights Into the Unique TetR-Dependent Regulation of a Drug Efflux Pump in Mycobacterium abscessus. Richard M, Gutierrez AV, Viljoen AJ, Ghigo E, Blaise M, Kremer L; Front Microbiol. 2018;9:649. PMID:29675007