Tryptophan-associated transmembrane protein (Trp_oprn_chp)
Members of this family are predicted transmembrane proteins with four membrane-spanning helices. Members are found in the Actinobacteria (Mycobacterium, Corynebacterium, Streptomyces), always associated with genes for tryptophan biosynthesis.
Jiyao W et al.(2023). "The conserved domain database in 2023.",