This domain is found at the C-terminal end of Activated RNA polymerase II transcriptional coactivator p15 from humans, YdbC from Lactococcus lactis, and other PC4 family members. p15 has a bipartite structure composed of an N-terminal regulatory domain and a carboxy-terminal cryptic DNA-binding domain [1-4]. Activity is controlled by protein kinases that target the regulatory domain.

1: A novel mediator of class II gene transcription with homology to viral immediate-early transcriptional regulators. Kretzschmar M, Kaiser K, Lottspeich F, Meisterernst M; Cell 1994;78:525-534. PMID:8062392

2: Structures of apo- and ssDNA-bound YdbC from Lactococcus lactis uncover the function of protein domain family DUF2128 and expand the single-stranded DNA-binding domain proteome. Rossi P, Barbieri CM, Aramini JM, Bini E, Lee HW, Janjua H, Xiao R, Acton TB, Montelione GT; Nucleic Acids Res. 2013;41:2756-2768. PMID:23303792

3: C-terminal domain of transcription cofactor PC4 reveals dimeric ssDNA binding site. Brandsen J, Werten S, van der Vliet PC, Meisterernst M, Kroon J, Gros P; Nat Struct Biol. 1997;4:900-903. PMID:9360603

4: Insights on the disruption of the complex between human positive coactivator 4 and p53 by small molecules. Pandey B, Dev A, Chakravorty D, Bhandare VV, Polley S, Roy S, Basu G; Biochem Biophys Res Commun. 2021;578:15-20. PMID:34534740