This domain is found in Signal transducer and activator of transcription proteins (STAT) from animals. These proteins are activated in response to extracellular signals such as cytokines, growth factors and hormonal factors and translocate to the nucleus, where they bind to specific promoter sequences in target genes. This entry represents the all-helical linker domain that connects the DNA binding domain (Pfam:PF02864) and the SH2 domain (Pfam:PF00017) [1-5].

1: Crystal structure of a tyrosine phosphorylated STAT-1 dimer bound to DNA. Chen X, Vinkemeier U, Zhao Y, Jeruzalmi D, Darnell JE Jr, Kuriyan J; Cell. 1998;93:827-839. PMID:9630226

2: Three-dimensional structure of the Stat3beta homodimer bound to DNA. Becker S, Groner B, Muller CW; Nature 1998;394:145-151. PMID:9671298

3: Structure of the unphosphorylated STAT5a dimer. Neculai D, Neculai AM, Verrier S, Straub K, Klumpp K, Pfitzner E, Becker S; J Biol Chem. 2005;280:40782-40787. PMID:16192273

4: Structural bases of unphosphorylated STAT1 association and receptor binding. Mao X, Ren Z, Parker GN, Sondermann H, Pastorello MA, Wang W, McMurray JS, Demeler B, Darnell JE Jr, Chen X; Mol Cell. 2005;17:761-771. PMID:15780933

5: Crystal structure of unphosphorylated STAT3 core fragment. Ren Z, Mao X, Mertens C, Krishnaraj R, Qin J, Mandal PK, Romanowski MJ, McMurray JS, Chen X; Biochem Biophys Res Commun. 2008;374:1-5. PMID:18433722