DsbA is a double stranded binding protein found in bacteriophage T4 which is involved in transcriptional regulation. DsbA, along with other viral proteins, interacts with the host RNA polymerase core enzyme enabling initiation of transcription. DsbA acts as an enhancer protein of late genes in vitro. The protein consists of mainly alpha helices [1].

1: Overexpression and structural characterization of the phage T4 protein DsbA. Sieber P, Lindemann A, Boehm M, Seidel G, Herzing U, van der Heusen P, Muller R, Ruger W, Jaenicke R, Rosch P; Biol Chem. 1998;379:51-58. PMID:9504717